Intracranial Arterial Stenosis

Preliminary findings on diagnostic performance of computed tomography perfusion images for intracranial arterial stenosis: a retrospective study

OBJECTIVES

Computed tomographic perfusion (CTP) can play an auxiliary role in the selection of patients with acute ischemic stroke for endovascular treatment. However, data on CTP in non-stroke patients with intracranial arterial stenosis are scarce. We aimed to investigate images in patients with asymptomatic intracranial arterial stenosis to determine the detection accuracy and interpretation time of large/medium-artery stenosis or occlusion when combining computed tomographic angiography (CTA) and CTP images.

METHODS

We retrospectively reviewed 39 patients with asymptomatic intracranial arterial stenosis from our hospital database from January 2021 to August 2023 who underwent head CTP, head CTA, and digital subtraction angiography (DSA). Head CTA images were generated from the CTP data, and the diagnostic performance for each artery was assessed. Two readers independently interpreted the CTA images before and after CTP, and the results were analyzed.

RESULTS

After adding CTP maps, the accuracy (area under the curve) of diagnosing internal carotid artery (R1: 0.847 vs. 0.907, R2: 0.776 vs. 0.887), middle cerebral artery (R1: 0.934 vs. 0.933, R2: 0.927 vs. 0.981), anterior cerebral artery (R1: 0.625 vs. 0.750, R2: 0.609 vs. 0.750), vertebral artery (R1: 0.743 vs. 0.764, R2: 0.748 vs. 0.846), and posterior cerebral artery (R1: 0.390 vs. 0.575, R2: 0.390 vs. 0.585) occlusions increased for both readers (p < 0.05). Mean interpretation time (R1: 72.4 ± 6.1 s vs. 67.7 ± 6.4 s, R2: 77.7 ± 3.8 s vs. 72.6 ± 4.7 s) decreased when using a combination of both images both readers (p < 0.001).

CONCLUSIONS

The addition of CTP images improved the accuracy of interpreting CTA images and reduced the interpretation time in asymptomatic intracranial arterial stenosis. These findings support the use of CTP imaging in patients with asymptomatic intracranial arterial stenosis.

Epidemiology, Pathophysiology, and Imaging of Atherosclerotic Intracranial Disease

Intracranial atherosclerotic disease (ICAD) is one of the most common causes of stroke worldwide. Among people with stroke, those of East Asia descent and non-White populations in the United States have a higher burden of ICAD-related stroke compared with Whites of European descent. Disparities in the prevalence of asymptomatic ICAD are less marked than with symptomatic ICAD. In addition to stroke, ICAD increases the risk of dementia and cognitive decline, magnifying ICAD societal burden. The risk of stroke recurrence among patients with ICAD-related stroke is the highest among those with confirmed stroke and stenosis ≥70%. In fact, the 1-year recurrent stroke rate of >20% among those with stenosis >70% is one of the highest rates among common causes of stroke. The mechanisms by which ICAD causes stroke include plaque rupture with in situ thrombosis and occlusion or artery-to-artery embolization, hemodynamic injury, and branch occlusive disease. The risk of stroke recurrence varies by the presumed underlying mechanism of stroke, but whether techniques such as quantitative magnetic resonance angiography, computed tomographic angiography, magnetic resonance perfusion, or transcranial Doppler can help with risk stratification beyond the degree of stenosis is less clear. The diagnosis of ICAD is heavily reliant on lumen-based studies, such as computed tomographic angiography, magnetic resonance angiography, or digital subtraction angiography, but newer technologies, such as high-resolution vessel wall magnetic resonance imaging, can help distinguish ICAD from stenosing arteriopathies.

Evaluation of peripapillary retinal nerve fiber layer thickness in intracranial atherosclerotic stenosis

PURPOSE

To evaluate the peripapillary retinal nerve fiber layer thickness (pRNFL) in patients with intracranial atherosclerotic stenosis (ICAS).

METHODS

A cross-sectional study was performed in a general hospital. The intracranial atherosclerotic stenosis was evaluated by digital subtraction angiography (DSA), computed tomography angiography (CTA) or magnetic resonance angiography (MRA). High-definition optical coherence tomography (HD-OCT) was used to evaluate the peripapillary retinal nerve fiber layer thickness.

RESULTS

A total of 102 patients, including 59(57.8%) patients with ICAS and 43(42.2%) patients without ICAS, were finally analysed in the study. The peripapillary retinal nerve fiber layer thickness (pRNFL) was reduced significantly in the average, the superior and the inferior quadrants of the ipsilateral eyes and in the superior quadrant of the contralateral eyes in patients with ICAS compared with patients without ICAS. After multivariate analysis, only the superior pRNFL thickness in the ipsilateral eyes was significantly associated with ICAS (OR,0.968; 95% CI,0.946-0.991; p = 0.006). The area under receiver operator curve was 0.679 (95% CI,0.576-0.782) for it to identify the presence of ICAS. The cut-off value of the superior pRNFL was 109.5 μm, and the sensitivity and specificity were 50.8% and 83.7%, respectively.

CONCLUSION

The superior pRNFL in the ipsilateral eye was significantly associated with ICAS in this study. Larger studies are needed to explore the relation between pRNFL and ICAS further.

Demographic and risk factors profile of intracranial atherosclerotic stenosis in the Kingdom of Bahrain

Background

Intracranial atherosclerotic stenosis (ICAS) is one of the most common causes of stroke worldwide. This study aimed to analyze the demographic and risk factor profiles of ICAS in the Kingdom of Bahrain. The study population included 477 patients who were hospitalized in the Neurology Department from March 1, 2018, to September 1, 2020 because of acute ischemic stroke and underwent arterial brain imaging (CTA or MRA) examination during their hospitalization.

Results

Of 477 patients, 123 (25.7%) had ICAS. A history of stroke/transient ischemic attack was significantly higher in patients with intracranial stenosis (P = 0.012). Patients with ICAS had significant concurrent extracranial arterial stenosis (ECAS) (P = 0.00). In Bahraini patients, dyslipidemia was associated with a higher percentage of developing ICAS, but this was statistically nonsignificant (p = 0.06).

Conclusions

An independent and significant correlation was found between ICAS and stroke recurrence. In addition, a concurrent existence of ECAS and ICAS was noted.

Application of Three-Dimensional Arterial Spin Labeling Technique in the Assessment of Cerebral Blood Perfusion in Patients with Middle Cerebral Artery Occlusion: Analysis of Clinical Implications and Prognostic Factors

Objective. To explore the value of three-dimensional- (3D-) arterial spin labeling (ASL) technique in evaluating cerebral perfusion in patients with unilateral middle cerebral artery occlusion (MCAO) and to observe the influencing factors of poor prognosis via long-term follow-up of patients who survived the disease. Methods. The clinical data of 60 patients with unilateral middle cerebral artery (MCA) M1 segment occlusion diagnosed by magnetic resonance angiography (MRA) from January 2018 to January 2022 were retrospectively analyzed. All patients were examined by routine MRI, MRA, and 3D-ASL, in which two postlabeling delays (PLDs; 1525 ms and 2525 ms) were used in 3D-ASL. Cerebral blood flow (CBF) in the regions of interest (ROIs) of MCA on the affected side and the mirror side was measured. The clinical data and laboratory indexes of patients were collected and evaluated by clinical scales. With the modified Rankin Score (mRS) as the outcome indicator, patients were assigned to either the poor or the good prognosis group to analyze the factors influencing patient prognosis via univariate and multivariate analyses. Results. Among unilateral MCAO patients, there was a significant difference in the CBF of the affected side between the PLD 1525 ms and 2525 ms groups ( $P<0.05$ ), but there was no significant difference in the CBF of the mirror side ( $P>0.05$ ). Compared with the mirror side, 43 cases (71.7%) of the affected CBF presented with hypoperfusion, 9 cases (15.0%) with normal perfusion, and 8 cases (13.3%) with hyperperfusion. Age, NIHSS score, collateral circulation, and homocysteine (Hcy) were identified by multivariate Logistic regression analysis as independent risk factors for adverse outcomes. Conclusion. MCAO can lead to cerebral blood perfusion decline, and 3D-ASL technique can evaluate the post-MCAO cerebral blood perfusion level. Old age, high NIHSS scores, poor collateral circulation, and high Hcy levels are associated with poor clinical outcomes.

Association Between Serum Uric Acid and Intracranial Arterial Stenosis in a Korean Population: A Secondary Analysis Based on a Cross-Sectional Study

Background and purpose

Intracranial arterial stenosis (ICAS) is a common cause of cerebrovascular disease. Studies have shown that the disease may be associated with elevated serum uric acid. However, the results remain inexact and controversial. To provide theoretical support for clinical practice, we assessed the relationship between uric acid and ICAS based on previous literature.

Materials and Methods

A total of 1,011 samples were included in the secondary cross-sectional study we investigated. We evaluated the relationship between uric acid level and ICAS using multivariable logistic regression analysis.

Results

The mean age of patients was 64.16 ± 9.13 years, and 35.51% (n = 359) were male in the study. One hundred and one (10%) of the included participants had ICAS. In the unadjusted model, uric acid level was positively associated with ICAS [odds ratio (OR) = 1.23, 95% confidence interval (CI): 1.07–1.42, p < 0.01]. After adjusting for potential confounders (sex, age, diabetes mellitus, coronary artery occlusive disease, hyperlipidemia, statin medication, hypertension, and fasting glucose), a positive relationship was observed between uric acid and ICAS (OR = 1.26, 95% CI: 1.08–1.47, p < 0.05).

Conclusion

There was a positive relationship between uric acid levels and ICAS in neurologically healthy Korean participants.

Evaluation of intracranial artery stenosis using time-of-flight magnetic resonance angiography: new wine in an old bottle

KEY POINTS

• TOF MRA is very important in the evaluation of cerebrovascular stenosis, and a novel evaluation system can further enhance its strengths.• This evaluation system is more accurate based on the fact that cerebral vascular stenosis alters hemodynamics and leads to different imaging presentations.

Standard-Dose Atorvastatin Treatment in Patients With Symptomatic Middle Cerebral Artery Atherosclerotic Stenosis: A Vessel Wall Magnetic Resonance Imaging Study

Background and Purpose: Ischemic stroke can be caused by atherosclerotic lesions of the middle cerebral artery (MCA). Some studies have described the effects of statin treatment on carotid artery plaques, but little is known about the effects of statin treatment on MCA plaques. The purpose of this study was to validate the efficacy of standard-dose atorvastatin (20 mg/day) in patients with symptomatic MCA atherosclerotic stenosis (SMAS) in northern China.

Materials and Methods: This study is a prospective, single-arm, single-center, 12-month follow-up observational study monitoring imaging, and clinical outcomes of standard-dose atorvastatin treatment among patients with SMAS. The primary outcomes were changes in vessel wall magnetic resonance imaging (VWMRI) and serum lipid profiles before and after (1, 3, 6, and 12 months) statin treatment.

Results: A total of 46 patients were recruited for this study, and 24 patients completed the follow-up. During the follow-up period, serum non-high-density lipoprotein cholesterol concentrations gradually decreased in the patients. Fourteen patients (54.33%) had a reversal of MCA plaques and 10 patients (41.67%) had no significant progression of MCA plaques and remained stable at the follow-up endpoint. At the 12 months follow-up time-point, the treatment did not reverse vascular remodeling or change the shape and distribution of plaques. Altered serum low-density lipoprotein cholesterol (LDL-C) concentrations in patients were strongly associated with plaque reversal.

Conclusion: Vessel wall magnetic resonance imaging could accurately characterize changes in MCA plaques after lipid-lowering therapy. Standard-dose atorvastatin treatment could stabilize and reverse plaques in northern Chinese patients with SMAS.

Diabetes, Vascular Aging and Stroke: Old Dogs, New Tricks?

BACKGROUND

Stroke remains a leading cause of death and disability throughout the world. It is well established that Diabetes Mellitus (DM) is a risk factor for stroke, while other risk factors include dyslipidaemia and hypertension. Given that the global prevalence of diabetes steadily increases, the need for adequate glycaemic control and prevention of DM-related cardiovascular events remains a challenge for the medical community. Therefore, a re-examination of the latest data related to this issue is of particular importance.

OBJECTIVE

This review aims to summarise the latest data on the relationship between DM and stroke, including epidemiology, risk factors, pathogenesis, prevention and biomarkers.

METHODS

For this purpose, comprehensive research was performed on the platforms PubMed, Google Scholar and EMBASE with a combination of the following keywords: diabetes mellitus, stroke, macrovascular complications, diabetic stroke, cardiovascular disease.

CONCLUSIONS

Much progress has been made in stroke in people with DM in terms of prevention and early diagnosis. In the field of prevention, the adaptation of the daily habits and the regulation of co-morbidity of individuals play a particularly important role. Simultaneously, the most significant revolution has been brought by the relatively new treatment options that offer protection to the cardiovascular system. Moreover, many prognostic and diagnostic biomarkers have been identified, paving the way for early and accurate diagnoses. However, to date, there are crucial points that remain controversial and need further clarification.

The feasibility of non-contrast-enhanced zero echo time magnetic resonance angiography for characterization of intracranial atherosclerotic disease

Background

Accurate and non-invasive assessment of intracranial atherosclerotic disease (ICAD) is important because of its effect on treatment planning. The aim of this study is to investigate if zero echo time (zTE) magnetic resonance angiography (zTE-MRA) is feasible in the characterization of ICAD.

Methods

A total of 175 patients with ICAD were recruited. ZTE-MRA and time-of-flight (TOF)-MRA sequences were conducted for all participants using a 3T clinical MR system. Forty-one patients also underwent digital subtraction angiography (DSA), and were confirmed to have intracranial arterial stenosis (ICAS). Weighted kappa (κ) statistics were used to assess the inter-observer agreement and diagnostic consistency of both zTE- and TOF-MRA, using DSA as a reference. The Wilcoxon signed-rank test was used to evaluate differences in image quality between zTE- and TOF-MRA images. The nonparametric test of multiple paired samples was used to compare the results of vascular stenosis diagnosis between zTE-, TOF-MRA and DSA.

Results

Supported by high inter-observer agreement (weighted κ=0.78), zTE-MRA generated significantly higher scores than TOF-MRA for susceptibility artifact signal (mean: 3.03±0.98 vs. 2.72±1.09; P=0.017) and flow signal in parent artery (mean: 3.63±0.49 vs. 3.07±0.82; P<0.001). Additionally, zTE-MRA showed more robust diagnostic performance than TOF-MRA for patients with ICAD and degree of vascular stenosis (P<0.05), and was highly consistent with reference DSA images (weighted κ=0.80).

Conclusions

ZTE-MRA has potential for use as a routine clinical method for patients with ICAD.

Asymmetrical Bioimpedance in the Anterior Circulation for Urgent Stratification of suspected Stroke (ABACUS Stroke): study protocol for a diagnostic accuracy study

BACKGROUND

Early identification and treatment of stroke improve outcome. Ischaemic stroke due to large vessel occlusion (LVO) benefits from time-critical thrombectomy but this is only available in highly specialised healthcare services. Cerebral Bioimpedance Asymmetry (CBA) measurement obtained with the portable and rapid Cerebrotech Visor™ System device may be able to identify certain types of stroke including LVO. This test could be deployed pre-hospital and used to immediately direct patients to the most appropriate healthcare service for treatment. This study is evaluating the diagnostic accuracy of CBA measurements obtained from a real-world population of suspected stroke.

METHODS

Study design: Prospective observational cohort study.Setting: A hyperacute stroke unit and neuroscience centre in North East England.Participants: Adults with a paramedic assigned diagnosis of suspected stroke arriving at hospital within 6 hours of symptom onset.Index Test: Cerebral Bioimpedance Asymmetry measurement performed using the Cerebrotech Visor™ System. Measurement values produce continuous data (range 0 -100); pre-defined threshold for positive state ≥ 10.Reference Standard Tests: Standard CT brain +/- CT/MR angiography, and expert clinician opinion will establish the following clinical outcomes which constitute the suspected stroke population: ischaemic stroke +/- large vessel occlusion; symptomatic severe anterior vessel stenosis; large (≥60ml) and small (<60mls) vessel intracerebral haemorrhage; transient ischaemic attack; stroke mimic conditions; prior territorial stroke.Analyses: Sensitivity, specificity, negative and positive predictive values, area under the Receiver Operating Characteristic curve for identification of i) "complex stroke" (ischaemic stroke with large vessel occlusion or symptomatic severe anterior vessel stenosis or intracerebral haemorrhage ≥60ml or prior territorial stroke) and ii) ischaemic stroke with large vessel occlusion in isolation.Sample size: 124 participants.

DISCUSSION

The results from this study will determine how accurately CBA measurement using the Cerebrotech Visor™ System can identify key stroke types within the suspected stroke population. Acceptable diagnostic performance would be an important step forwards for access to time-critical treatments.

TRIAL REGISTRATION

Registered with ISRCTN (identifier: ISRCTN79169844) on 06/08/2018.

Association of antinuclear antibodies with the risk of intracranial arterial stenosis

The prevalence of intracranial arterial stenosis (IAS) as well as antinuclear antibody (ANA) positivity was found to be higher in Asians than that in the Western population. To investigate the relation of ANAs with IAS in patients with acute ischemic cerebrovascular disease, we enrolled 2492 patients with acute ischemic stroke or transient ischemic attack into the study. All the patients were categorized into 3 groups according to the IAS burden. Multinomial logistic regression analyses were used in statistical analysis. The positive rate of ANAs in the IAS ≥ 2 group was higher than that in the single IAS group and the no IAS group (p<0.001). The adjusted odds ratio (OR) for IAS ≥ 2 in ANAs-positive patients was 3.737 (95%CI=2.676-5.220, p<0.001) compared with the ANAs-negative patients. ANAs were associated with multiple IAS rather than single IAS in both male and female subgroups. Besides, ANAs were significantly associated with single and multiple IAS in individuals ≤ 60 years. However, ANAs were only associated with two or more IAS in two age groups (between 61 to 75 years and >75 years old). In summary, ANAs are associated with IAS in patients with acute ischemic cerebrovascular disease.

Regression of asymptomatic intracranial arterial stenosis by aggressive medical management with a lipid-lowering agent

Objective

The incidence rate of stroke as a result of intracranial arterial stenosis (ICAS) is higher in Asian countries than in the West. We aimed to analyze the regression, lack of change, or progression of asymptomatic ICAS after the administration of rosuvastatin and associated factors.

Methods

The patients who had undergone computed tomography angiography (CTA) at our hospital and had been diagnosed with ICAS with no ischemic event in the stenosed vascular territory were included in the study. They were administered 20mg of rosuvastatin per day. After a follow-up period of at least 6 months after treatment, the patients were examined using CTA again and the clinical information and imaging results were analyzed.

Results

In total, 48 patients were diagnosed with asymptomatic ICAS. During the final follow-up examination, it was found that the stenotic lesion regressed in 30 patients, whereas it remained unchanged or progressed without any adverse effects in 18 patients. In univariate analysis, the regressed group showed significantly higher differences in the levels of total cholesterol and low-density lipoprotein (LDL) between their initial and final values (both, p=0.031 for both). In the multivariate analysis, a significantly higher difference in the levels of LDL between its initial and final measurement was seen in the regressed group (p=0.035, odds ratio(OR) 3.9).

Conclusions

Rosuvastatin was found to have better lipid-lowering effects for total cholesterol and particularly LDL in patients whose ICAS had regressed. We concluded that rosuvastatin administration can be recommended for the treatment of patients with asymptomatic ICAS.

Cerebral Arterial Stiffness as A New Marker of Early Stage Atherosclerosis of The Cerebral Large Artery in Acute Stroke

Aim: Carotid–cer ebral pulse wave velocity (ccPWV) reflects the segment (C-M segment) stiffness between the common carotid artery and ipsilateral middle cerebral artery. C-M segment atherosclerosis (CMSA) is regarded the most frequent cause of anterior circulation ischemic stroke. We aimed to evaluate the association of ccPWV with early stage CMSA in this study.

Methods: Eighty-one acute ischemic stroke (AIS) patients with 154 C-M segments who were successfully evaluated with digital subtraction angiography, ccPWV, carotid intima–media thickness (cIMT), and brachial–ankle pulse wave velocity were enrolled into this study. Patient demographics and clinical data were retrieved from our AIS databases.

Results: Multivariate analyses showed that CMSA was independently associated with higher systolic BP, ccPWV, and cIMT. ccPWV and cIMT presented good diagnostic values for evaluating early stage CMSA in the receiver operating characteristic curve analyses. The areas under the curve (AUCs) of ccPWV were significantly higher than that of cIMT (Z = 2.204, P = 0.007). The AUC, sensitivity, specificity, Youden index, and cutoff of ccPWV for detecting early stage CMSA were 0.815 (P < 0.001), 86%, 70.7%, 0.567, and 5.4 m/s, respectively. Furthermore, ccPWV was significantly correlated with the stenosis of CMSA at the early stage in Spearman's correlation analyses (r = 0.877, P < 0.001) and fractional polynomial plot with 95% confidence intervals.

Conclusions: Cerebral arterial stiffness has the potential to be a new marker of early stage atherosclerosis of the cerebral large artery. This finding may help us prevent the occurrence of stroke and decrease the burden of society from stroke patients.

Risk factors for intracranial atherosclerosis: A systematic review and meta-analysis

BACKGROUND AND AIMS

Intracranial atherosclerosis (ICAS) is a predictable and preventable condition, but existing evidence concerning its risk factors has not been quantitatively assessed. The aim of this meta-analysis is to identify the non-modifiable and modifiable risk factors for ICAS.

METHODS

PubMed and EMBASE were searched (1995-May 15, 2018) for cross-sectional and longitudinal studies exploring risk factors for ICAS. The risk estimates and 95% confidence intervals (CIs) in multivariate analysis were aggregated using random-effect models.

RESULTS

Thirty-four studies comprising 59,736 subjects met the inclusion criteria for the systematic review involving thirty-one risk or protective factors. Seven factors were associated with ICAS, as suggested by the meta-analysis, including advanced age (odds ratio (OR) 1.05, 95% CI 1.03-1.08), metabolic syndrome (OR 2.13, 95% CI 1.35-3.37), diabetes mellitus (OR 1.98, 95% CI 1.69-2.31), hypertension (OR 1.97, 95% CI 1.69-2.31), dyslipidemia (OR 1.29, 95% CI 1.04-1.59), high levels of low-density lipoprotein cholesterol (OR 1.06, 95% CI 1.00-1.12) and high levels of apolipoprotein A1 (OR 0.34, 95% CI 0.15-0.75). The subgroup analysis for study populations indicated advanced age, metabolic syndrome, diabetes mellitus and hypertension as an elevated risk of ICAS among community subjects and stroke patients; according to the subgroup analysis for ethnicity, similar associations remained in Asians, but only metabolic syndrome and diabetes mellitus were correlated with ICAS in Caucasians.

CONCLUSIONS

Individuals with advanced age, metabolic syndrome, diabetes mellitus, hypertension and dyslipidemia might have a higher risk of ICAS, whereas high levels of apolipoprotein A1 might protect against ICAS.

STA-Distal ACA Bypass Using a Contralateral STA Interposition Graft for Symptomatic ACA Stenosis

Intracranial arterial stenosis usually occurs due to atherosclerosis and is considered the most common cause of stroke worldwide. Although the effectiveness of bypass surgery for ischemic stroke is controversial, the superficial temporal artery to the middle cerebral artery bypass for ischemic stroke is a common procedure. In our report, a 50-year-old man presented with sudden-onset left side weakness and dysarthria. An angiogram showed significant stenosis in the junction of the right cavernous-supraclinoid internal carotid artery and right pericallosal artery. Symptoms altered between improvement and deterioration. Magnetic resonance imaging showed a repeated progression of anterior cerebral artery (ACA) infarction despite maximal medical therapy. We performed a STA-ACA bypass with contralateral STA interposition. Postoperative course was uneventful with no further progression of symptoms. Thus, bypass surgery may be considered in patients with symptomatic stenosis or occlusion of the ACA, especially when patients present progressive symptoms despite maximal medical therapy.

Association Between the Apolipoprotein E Gene Polymorphism and Atherosclerotic Middle Cerebral Artery Stenosis

OBJECTIVES

Stenosis of the intracranial large arteries, especially the middle cerebral artery (MCA), is common in the Chinese population. We conducted a case-control study to investigate clinical and apolipoprotein E (ApoE) gene polymorphism of MCA atherosclerosis in the Chinese population.

MATERIALS AND METHODS

Polymerase chain reaction-based protocols were used to identify the genotypes of polymorphisms in ApoE genes. Clinical parameters and the genotypes of polymorphisms in the ApoE genes were compared in patients with and without MCA stenosis. The ApoE exon ε4 genotypes with risk factors were compared in the patients with and without MCA stenosis.

RESULTS

In total, 337 ischemic stroke patients were recruited, 156 cases with and 181 without MCA stenosis. Univariate analysis showed that the levels of systolic blood pressure and pulse pressure were higher in the MCA-stenosis group. There were no significant differences in the genotype and allele frequencies of the ApoE polymorphism observed between patients with and without MCA stenosis. However, there was a trend that the MCA-stenosis group tended to have more of genotype ε4/ε4 (3.8% vs. 0.6%, P=0.052) than the non-MCA-stenosis group. There was no effect of ApoE genotype and genotype-by-environment interactions on ischemic stroke susceptibility.

CONCLUSIONS

This present study indicated that the hypertension (ie, systolic blood pressure and pulse pressure) and the ApoEε4/ε4 genotype may be associated with the occurrence of MCA stenosis in the ischemic stroke Chinese patients.

Quantitative assessment of symptomatic intracranial atherosclerosis and lenticulostriate arteries in recent stroke patients using whole-brain high-resolution cardiovascular magnetic resonance imaging

BACKGROUND

It has been shown that intracranial atherosclerotic stenosis (ICAS) has heterogeneous features in terms of plaque instability and vascular remodeling. Therefore, quantitative information on the changes of intracranial atherosclerosis and lenticulostriate arteries (LSAs) may potentially improve understanding of the pathophysiological mechanisms underlying stroke and may guide the treatment and work-up strategies. Our present study aimed to use a novel whole-brain high-resolution cardiovascular magnetic resonance imaging (WB-HRCMR) to assess both ICAS plaques and LSAs in recent stroke patients.

METHODS

Twenty-nine symptomatic and 23 asymptomatic ICAS patients were enrolled in this study from Jan 2015 through Sep 2017 and all patients underwent WB-HRCMR. Intracranial atherosclerotic plaque burden, plaque enhancement volume, plaque enhancement index, as well as the number and length of LSAs were evaluated in two groups. Enhancement index was calculated as follows: ([Signal intensity (SI)plaque/SInormal wall on post-contrast imaging] - [SIplaque/SInormal wall on matched pre-contrast imaging])/(SIplaque / SInormal wall on matched pre-contrast imaging). Logistic regression analysis was used to investigate the independent high risk plaque and LSAs features associated with stroke.

RESULTS

Symptomatic ICAS patients exhibited larger enhancement plaque volume (20.70 ± 3.07 mm3 vs. 6.71 ± 1.87 mm3 P = 0.001) and higher enhancement index (0.44 ± 0.08 vs. 0.09 ± 0.06 P = 0.001) compared with the asymptomatic ICAS. The average length of LSAs in symptomatic ICAS (20.95 ± 0.87 mm) was shorter than in asymptomatic ICAS (24.04 ± 0.95 mm) (P = 0.02). Regression analysis showed that the enhancement index (100.43, 95% CI - 4.02-2510.96; P = 0.005) and the average length of LSAs (0.80, 95% CI - 0.65-0.99; P = 0.036) were independent factors for predicting of stroke.

CONCLUSION

WB-HRCMR enabled the comprehensive quantitative evaluation of intracranial atherosclerotic lesions and perforating arteries. Symptomatic ICAS had distinct plaque characteristics and shorter LSA length compared with asymptomatic ICAS.

Analysis of Radiation Effects in Digital Subtraction Angiography of Intracranial Artery Stenosis

BACKGROUND

Intracranial artery stenosis (IAS) is the most common cause for acute cerebral accidents. Digital subtraction angiography (DSA) is the gold standard to detect IAS and usually brings excess radiation exposure to examinees and examiners. The artery pathology might influence the interventional procedure, causing prolonged radiation effects. However, no studies on the association between IAS pathology and operational parameters are available.

METHODS

A retrospective analysis was conducted on 93 patients with first-ever stroke/transient ischemic attack, who received DSA examination within 3 months from onset in this single center. Comparison of baseline characteristics was determined by 2-tailed Student's t-test or the chi-square test between subjects with and without IAS. A binary logistic regression analysis was performed to determine the association between IAS pathology and the items with a P value <0.05 in Student's t-test or chi-square test.

RESULTS

There were 93 candidates (42 with IAS and 51 without IAS) in this study. The 2 groups shared no significance of the baseline characteristics (P > 0.05). We found a significantly higher total time, higher kerma area product, greater total dose, and greater DSA dose in the IAS group than in those without IAS (P < 0.05). A binary logistic regression analysis indicated the significant association between total time and IAS pathology (P < 0.05) but no significance in kerma area product, radiation dose, and DSA dose (P > 0.05).

CONCLUSIONS

IAS pathology would indicate a prolonged total time of DSA procedure in clinical practice. However, the radiation effects would not change with pathologic changes.

Importance of Collateralization in Patients With Large Artery Intracranial Occlusive Disease: Long-Term Longitudinal Assessment of Cerebral Hemodynamic Function

Patients with large artery intracranial occlusive disease (LAICOD) are at risk for both acute ischemia and chronic hypoperfusion. Collateral circulation plays an important role in prognosis, and imaging plays an essential role in diagnosis, treatment planning, and prognosis of patients with LAICOD. In addition to standard structural imaging, assessment of cerebral hemodynamic function is important to determine the adequacy of collateral supply. Among the currently available methods of assessment of cerebral hemodynamic function, measurement of cerebrovascular reactivity (CVR) using blood oxygen level-dependent (BOLD) MRI and precisely controlled CO₂ has shown to be a safe, reliable, reproducible, and clinically useful method for long-term assessment of patients. Here, we report a case of long-term follow-up in a 28-year-old Caucasian female presented to the neurology clinic with a history of TIAs and LAICOD of the right middle cerebral artery (MCA). Initial structural MRI showed a right MCA stenosis and a small right coronal radiate lacunar infarct. Her CVR study showed a large area of impaired CVR with a paradoxical decrease in BOLD signal with hypercapnia involving the right MCA territory indicating intracerebral steal. The patient was managed medically with anticoagulant and antiplatelet therapy and was followed-up for over 9 years with both structural and functional imaging. Cortical thickness (CT) measures were longitudinally assessed from a region of interest that was applied to subsequent time points in the cortical region exhibiting steal physiology and in the same region of the contralateral healthy hemisphere. In the long-term follow-up, the patient exhibited improvement in her CVR as demonstrated by the development of collaterals with negligible changes to CT. Management of patients with LAICOD remains challenging since no revascularization strategies have shown efficacy except in patients with moyamoya disease. Management is well defined for acute ischemia where the presence and the adequacy of the collateralization dictate the need for intervention. Long-term assessment in neurovascular uncoupling (i.e., chronic ischemia) may reveal improvements in CVR as the durability of compensatory collaterals improve, even in cases with no intervention. Thus, assessment of cerebrovascular hemodynamics using CVR measurements coupled with time-of-flight MR angiography can be useful in the clinical management of patients with LAICOD.

Association of lipoprotein-associated phospholipase A2 mass with asymptomatic cerebral artery stenosis

Cerebral artery stenosis (CAS) is the most important causes of ischaemic stroke. Lipoprotein-associated phospholipase A2 (Lp-PLA2) plays 2 diverse roles in atherosclerosis (pro-inflammatory and anti-inflammatory), and the association between Lp-PLA2 mass and cardiovascular or cerebrovascular events is inconsistent among previous studies. A cross-sectional study including 2012 North Chinese adults aged ≥40 years was performed in 2010-2011 to investigate whether Lp-PLA2 mass is associated with asymptomatic cerebral artery stenosis (ACAS). Serum Lp-PLA2 mass was determined by enzyme-linked immunosorbent assay (ELISA). All participants underwent transcranial Doppler (TCD) and bilateral carotid duplex ultrasound to evaluate intracranial artery stenosis (ICAS) and extracranial arterial stenosis (ECAS). The median serum Lp-PLA2 mass of the participants was 140.74 ng/mL (interquartile range: 131.79-158.07 ng/mL). The adjusted odds ratio (OR) when comparing the 4th quartile to the 1st quartile of Lp-PLA2 was 1.98 (95% confidence interval (CI): 1.42-2.78), 1.79 (95% CI: 1.08-2.94) and 1.87 (95% CI: 1.28-2.73) for the occurrence of ACAS, asymptomatic ECAS and asymptomatic ICAS, respectively, after controlling for vascular risk factors. These independently significant associations remained statistically significant in the male or elderly subgroups, but not in females or middle-aged participants. Lp-PLA2 mass is positively correlated with subclinical atherosclerosis determined by ACAS, ICAS and ECAS in North Chinese, particularly in male and older participants, suggesting that serum Lp-PLA2 mass might be potential biomarker for the detection of ACAS in the adults.

Role of sLOX-1 in intracranial artery stenosis and in predicting long-term prognosis of acute ischemic stroke

OBJECTIVE

The role of sLOX-1 in acute ischemic stroke still remains unclear. This study aims to demonstrate the value of sLOX-1 in evaluating degrees of intracranial artery stenosis and to predict prognosis in stroke.

METHODS

Two hundred and seventy-two patients were included in this study and basic data were collected within 72 hr on admission. We assessed the association between sLOX-1 levels and stroke conditions in one-year duration. After adjusting for potential confounders, regression analyses were performed.

RESULTS

We found that sLOX-1 levels were increased significantly in severe patients compared to the mild stroke group (p = .011). After adjusting confounders, sLOX-1 was associated with a poor functional outcome in patients with an adjusted OR of 2. 946 (95% CI, 1.788-4.856, p < .001). There was also positive correlation between sLOX-1 levels and the degrees of intracranial artery stenosis in the different groups (p = .029).

CONCLUSIONS

Our study demonstrated that sLOX-1 levels could be used to evaluate the severity of stroke and the degrees of intracranial artery stenosis. Furthermore, sLOX-1 could be exploited to predict the long-term functional outcome of stroke.

A new formula for predicting the position of severe arterial stenosis

Noninvasive location of an occlusion or a severe stenosis in the arterial system is of a great interest for surgical interventions. Here, we present a new method to determine the location of arterial 99% stenosis in the arterial (sub) system. The method requires a measurement of propagation constant and the instantaneous flow rate or velocity at two sites of an arterial tree. The method was successfully tested using Womersley's oscillatory flow theory and the data obtained by a simulation of Fluid structure interaction (FSI). The effect of noise has been investigated to simulate experimental conditions. The results demonstrate that location of 99% severe stenosis could be accurately obtained. The spatial resolution was approximately a few centimeters and the differences between exact and computed values didn't exceed 13%. However, the identifications of stenotic sites decreased with the distance. Further investigation of the developed method in vivo and in vitro is required.

The cerebral circulation and cerebrovascular disease II: Pathogenesis of cerebrovascular disease

In this paper, we review the cerebral circulation and cerebrovascular disease (CVD) with an overview of the major types of CVD pathogenesis. These, as categorized here, are as follows: occlusive injury intrinsic to blood vessels, occlusive injury extrinsic to blood vessels, cerebral hypoperfusion, and cerebral hemorrhage. Following an overview of each of these categories, we conclude with a discussion of cerebral edema to illustrate how the pathological origins we covered can progress clinically. The content of this paper sets the stage for the detailed, clinically oriented discussion of stroke with which our series culminates in its subsequent Part III.

Study on material base and action mechanism of compound Danshen dripping pills for treatment of atherosclerosis based on modularity analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese medicine (TCM) has been widely used in China and its surrounding countries in clinical treatments for centuries-long time. However, due to the complexity of TCM constituents, both action mechanism and material base of TCM remain nearly unknown.

AIM OF THE STUDY

The present study was designed to uncover the action mechanism and material base of TCM in a low-cost manner.

MATERIALS AND METHODS

Compound Danshen dripping pills (DSP) is a widely used TCM for treatment of atherosclerosis, and was researched here to demonstrate the effectiveness of our method. We constructed a heterogeneous network for DSP, identified the significant network module, and analyzed the primary pharmacological units by performing GO and pathways enrichment analysis.

RESULTS

Two significant network modules were identified from the heterogeneous network of DSP, and three compounds out of four hub nodes in the network were found to intervene in the process of atherosclerosis. Moreover, 13 out of 20 enriched pathways that were ranked in top 10 corresponding to both the two pharmacological units were found to be involved in the process of atherosclerosis.

CONCLUSIONS

Quercetin, luteolin and apigenin may be the main active compounds which modulate the signaling pathways, such as metabolism of xenobiotics by cytochrome P450, retinol metabolism, etc. The present method helps reveal the action mechanism and material base of DSP for treatment of atherosclerosis.

Comparison of stent versus medical therapy for symptomatic patients with intracranial atherosclerotic stenosis: A meta-analysis

PURPOSE

To compare the outcomes of intracranial stent implantation and medical therapy for treatment of severe intracranial stenosis.

METHODS

Articles were identified from Medline, Cochrane, EMBASE, and Google Scholar published up to August 25, 2016. Eligible studies reported stroke occurrence, transient ischemic attack (TIA), and event-free survival rates in patients who suffered recent TIA or stroke caused by stenosis of a major intracranial artery and treated with either medical therapy or stenting. 4 studies enrolled a total 739 patients.

RESULTS

While no association between intracranial endovascular therapy and short-term stroke risk was found (pooled OR=1.349, 95% CI=0.541 to 3.367, P=0.521), significantly higher rate of stroke occurrence was observed in patients treated with stent therapy within 30days of treatment (pooled OR=3.143, 95% CI=1.755 to 5.628, P<0.001). No association was found between the type of treatment and TIA occurrence (pooled OR=0.702, 95% CI=0.277 to 1.781, P=0.457) and event-free survival rate (pooled HR=1.170, 95% CI=0.947 to 1.447, P=0.145).

CONCLUSION

Patients with symptomatic intracranial atherosclerotic stenosis undergoing stent therapy may have higher risk of short-term stroke.

Clinical usefulness of ankle brachial index and brachial-ankle pulse wave velocity in patients with ischemic stroke

Ankle brachial index (ABI) and brachial-ankle pulse wave velocity (baPWV) are widely used noninvasive modalities to evaluate atherosclerosis. Recently, evidence has increased supporting the use of ABI and baPWV as markers of cerebrovascular disease. This study sought to examine the relationship between ABI and baPWV with ischemic stroke. This study also aimed to determine which pathogenic mechanism, large artery disease (LAD) or small vessel disease (SVD), is related to ABI or baPWV. Retrospectively, 121 patients with ischemic stroke and 38 subjects with no obvious ischemic stroke history were recruited. First, ABI and baPWV were compared between the groups. Then, within the stroke group, the relevance of ABI and baPWV with regard to SVD and LAD, which were classified by brain magnetic resonance image (MRI) and magnetic resonance angiography (MRA) or computed tomography angiography (CTA) findings, was assessed. The baPWV was higher in the stroke group than non-stroke group (1,944.18±416.6 cm/s vs. 1,749.76±669.6 cm/s, P<0.01). Regarding LAD, we found that mean ABI value was lower in the group with extracranial large artery stenosis (P<0.01), and there was an inverse linear correlation between ABI and the grade of extracranial large artery stenosis (P<0.01). For SVD, there was a significant correlation between SVD and baPWV (2,057.6±456.57 cm/s in the SVD (+) group vs. 1,491±271.62 cm/s in the SVD (-) group; P<0.01). However, the grade of abnormalities detected in SVD did not correlate linearly with baPWV. These findings show that baPWV is a reliable surrogate marker of ischemic stroke. Furthermore, baPWV and ABI can be used to indicate the presence of small vessel disease and large arterial disease, respectively.

A novel method of artery stenosis diagnosis using transfer function and support vector machine based on transmission line model: A numerical simulation and validation study

BACKGROUND AND OBJECTIVE

Transfer function (TF) is an important parameter for the analysis and understanding of hemodynamics when arterial stenosis exists in human arterial tree. Aimed to validate the feasibility of using TF to diagnose arterial stenosis, the forward problem and inverse problem were simulated and discussed.

METHODS

A calculation method of TF between ascending aorta and any other artery was proposed based on a 55 segment transmission line model (TLM) of human artery tree. The effects of artery stenosis on TF were studied in two aspects: stenosis degree and position. The degree of arterial stenosis was specified to be 10-90% in three representative arteries: carotid, aorta and iliac artery, respectively. In order to validate the feasibility of diagnosis of artery stenosis using TF and support vector machine (SVM), a database of TF was established to simulate the real conditions of artery stenosis based on the TLM model. And a diagnosis model of artery stenosis was built by using SVM and the database.

RESULTS

The simulating results showed the modulus and phase of TF were decreasing sharply from frequency 2 to 10Hz with the stenosis degree increasing and displayed their unique and nonlinear characteristics when frequency is higher than 10Hz. The diagnosis results showed the average accuracy was above 76% for the stenosis from 10% to 90% degree, and the diagnosis accuracies of moderate (50%) and serious (90%) stenosis were 87% and 99%, respectively. When the stenosis degree increased to 90%, the accuracy of stenosis localization reached up to 94% for most of arteries.

CONCLUSIONS

The proposed method of combining TF and SVM is a theoretically feasible method for diagnosis of artery stenosis.

Different blood pressure indexes on intracranial arterial stenosis in Asymptomatic Polyvascular Abnormalities in Community study in China

BACKGROUND

The association between hypertension and cerebrovascular events is shown in some large-scale studies, but it remains unclear which blood pressure index is the most sensitive risk factor for cerebrovascular stenosis.

METHODS

We investigated the potential associations between different blood pressure indexes and intracranial arterial stenosis (ICAS) in the study. The population-based Asymptomatic Polyvascular Abnormalities in Community study examined asymptomatic intracranial arterial abnormalities in a Chinese population and included participants aged more than 40 years without a history of stroke, transient ischemic attack, and coronary heart disease. ICAS was diagnosed by transcranial Doppler sonography. Blood pressure was measured with a mercury manometer three times; an average result of SBP and DBP was used, and mean arterial pressure (MAP) and pulse pressure (PP) were calculated for the statistical analysis.

RESULTS

Out of the 4422 study participants, 711 (16.1%) showed an asymptomatic ICAS. After adjusting for age, waist circumference, drinking, diabetes, dyslipidemia, and blood concentration of uric acid, C-reactive protein, and homocysteine, ICAS was significantly associated with a higher SBP [from decile 6, odds ratio (OR) 3.093; 95% confidence interval (CI) 1.909, 5.012; P < 0.01), a higher MAP (from decile 7, OR 2.889; 95% CI 1.853, 4.504; P < 0.01), and a higher PP (from decile 5, OR 2.295;95% CI 1.463, 3.601; P < 0.01). Using a receiver-operating characteristic curve to estimate the predictive value of different blood pressure indexes for ICAS, SBP, MAP, and PP, were predictive indexes for ICAS and PP showed the largest predictive value (area under the curve = 0.737).

CONCLUSIONS

The current study results suggest that SBP, MAP, and PP are all associated with asymptomatic ICAS. PP may be the most sensitive index to predict ICAS.

Detection of Cerebral Vasculopathy by Transcranial Doppler in Children With Neurofibromatosis Type 1

Neurofibromatosis type 1 is characterized by nerve sheath neurofibromas associated with a number of additional clinical features, including cerebrovascular disease. The aim of this study was to use transcranial Doppler as a screening method for identifying cerebral vasculopathy in children with neurofibromatosis type 1. Forty children with neurofibromatosis type 1, aged 5 to 18 years old, were examined by transcranial Doppler. Patients presenting with hemodynamic features of arterial stenosis/occlusion on transcranial Doppler underwent magnetic resonance angiography to confirm the findings. Magnetic resonance angiography was performed on 4 children who exhibited a transcranial Doppler hemodynamic pattern indicative of cerebral vasculopathy. Among these cases, 2 presented internal carotid artery stenosis/occlusion, 1 had bilateral middle cerebral artery stenosis, and 1 presented a normal magnetic resonance angiography result. Transcranial Doppler can be used routinely in the investigation of cerebrovascular disease in neurofibromatosis type 1 patients, where magnetic resonance angiography can be subsequently applied to confirm the diagnosis, further contributing to the prevention of cerebrovascular events.

The association between ankle-brachial index and asymptomatic cranial-carotid stenosis: a population-based, cross-sectional study of 5440 Han Chinese

BACKGROUND AND PURPOSE

Routine screening for asymptomatic cranial-carotid stenosis (ACCS) is controversial and recommendation in clinical practice is vague. The ankle-brachial index (ABI) is reported as a predictor for cardiovascular disease. However, there is a scarcity of data about the association between abnormal ABI and ACCS. A population-based cross-sectional study was conducted to explore the relationship between ABI and ACCS.

METHODS

A sample of 5440 Chinese adults aged 40-94 years old was recruited from 2010 to 2011. The ABI was measured using a portable Doppler device and ACCS was evaluated by bilateral carotid duplex ultrasound and portable examination devices. A logistic regression model was used to analyse the association between ABI and ACCS after adjusting for potential confounding factors.

RESULTS

A low ABI was associated with ACCS [odds ratio (OR) 1.95, 95% confidence interval (CI) 1.42-2.67] after adjusting for potential confounders. When the data were stratified by age and sex, the correlation remained statistically significant in the male (OR 2.32, 95% CI 1.60-3.37) and elderly (OR 3.07, 95% CI 1.97-4.78) subgroups compared to the female (OR 1.26, 95% CI 0.67-2.39) and middle-aged groups (OR 1.27, 95% CI 0.77-2.12), respectively.

CONCLUSION

This study demonstrated that low ABI is a significant risk factor for ACCS in male and elderly Chinese adults.

Internal carotid artery stenting for intracranial atherosclerosis

Intracranial atherosclerotic disease is a significant cause of stroke in the United States. Much like coronary atherosclerosis, this disease leads to arterial stenosis secondary to the buildup of lipid-based plaques in intracranial vessels. Ischemic stroke may occur following thromboembolic events near the site of stenosis or from watershed ischemia secondary to cerebral hypoperfusion. While this disease has been treated with intracranial angioplasty and stenting and cerebrovascular bypass surgery, the current literature supports aggressive medical management with dual antiplatelet therapy, treatment of comorbidities such as hypertension, diabetes, and hyperlipidemia, and lifestyle modification. Intracranial angioplasty and stenting is reserved for cases of medical failure.

Reproducibility of Middle Cerebral Artery Stenosis Measurements by DSA: Comparison of the NASCET and WASID Methods

Purpose

To evaluate the intra- and inter-observer variability of the North American Symptomatic Carotid Endarterectomy Trial (NASCET) and Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) criteria for the evaluation of middle cerebral artery (MCA) stenosis using digital subtraction angiography (DSA).

Materials and Methods

DSA images of 114 cases with 131 stenotic MCAs were retrospectively analyzed. Two radiologists and a researcher measured the degree of MCA stenosis independently using both NASCET and WASID methods. To determine intra-observer agreement, all the observers reevaluated the degree of MCA stenosis 4 weeks later. The linear relation and coefficient of variation (CV) between the measurements made by the two methods were assessed by correlation coefficient and multi-factor analysis of variance (ANOVA), respectively. Intra- and inter-observer variability of the two methods was evaluated by intraclass correlation coefficient (ICC), Spearman’s R value, Pearson correlation coefficient and Bland-Altman plots.

Results

Despite the fact that the degree of MCA stenosis measured by NASCET was lower than measured using the WASID method, there was good linear correlation between the measurements made by the two methods (for the mean measurements of the 3 observers, NASCET% = 0.891 × WASID% - 1.89%; ICC, Spearman’s R value and Pearson correlation were 0.874, 0.855, and 0.874, respectively). The CVs of both intra- and inter-observer measurements of MCA stenosis using WASID were significantly lower than that using NASCET confirmed by the multi-factor ANOVA results, which showed only the measurement methods of MCA stenosis had significant effects on the CVs both in intra- and inter-observer measurements (both P values < 0.001). Intra-observer measurements showed good or excellent agreement with respect to WASID and NASCET evaluation (ICC, 0.656 to 0.817 and 0.635 to 0.761, respectively). Good agreement for the WASID evaluation (ICC, 0.592 to 0.628) and for the NASCET evaluation (ICC, 0.529 to 0.568) was observed for inter-observer measurements. Bland-Altman plots demonstrated that the WASID method had better reproducibility and intra-observer agreement than NASCET method for evaluating MCA stenosis.

Conclusion

Both NASCET and WASID methods have an acceptable level of agreement; however, the WASID method had better reproducibility for the evaluation of MCA stenosis, and thus the WASID method may serve as a standard for measuring the degree of MCA stenosis.

Impact of Intracranial Atherosclerotic Stenosis on the Prognosis in Acute Ischemic Stroke Patients with Cardioembolic Source

BACKGROUND AND AIM

In recent days, intracranial atherosclerotic stenosis (IAS) has been reportedly related to recurrent stroke and mortality in the total patient population with ischemic stroke. However, its impact on the prognosis of the patients with cardioembolic source is not yet established. This study attempted to investigate whether IAS was associated with poor outcome in stroke patients with cardioembolic source.

METHODS

Overall, 223 patients with acute ischemic stroke and cardioembolic source were included in this study. IAS was defined as ≥ 50% stenosis on enhanced MRA, and cardioembolic sources were detected by ECG and echocardiography. Follow-up data were obtained from outpatient medical records and/or telephone interviews.

RESULTS

Overall, 60 major clinical events causing poor outcome occurred in 58 patients (26.0%). Patients with IAS had significantly higher rates of death and stroke recurrence than those without IAS (p = 0.015 and 0.046 each by log rank test). The multivariate Cox proportional hazards regression analysis showed that IAS was significantly related to the poor outcome (hazard ratio 1.725, 95% confidence interval 1.020-2.920, p = 0.042).

CONCLUSIONS

In acute ischemic stroke patients with cardioembolic source, IAS may be considered a marker of a high risk of stroke recurrence or death.

Superior performance of cone-beam CT angiography in characterization of intracranial atherosclerosis

Object

Intracranial atherosclerotic disease (ICAD) carries a high risk of stroke. Evaluation of ICAD has focused on assessing the absolute degree of stenosis, although plaque morphology has recently demonstrated increasing relevance. The authors provide the first report of the use of ultra-high-resolution C-arm cone-beam CT angiography (CBCT-A) in the evaluation of vessel stenosis as well as plaque morphology.

Methods

Between August 2009 and July 2012, CBCT-A was used in all patients with ICAD who underwent catheter-based angiography at the authors' institution (n = 18). Lesions were evaluated for maximum degree of stenosis as well as plaque morphological characteristics (ulcerated, calcified, dissected, or spiculated) via digital subtraction angiography (DSA), 3D-rotational angiography (3DRA), and CBCT-A. The different imaging modalities were compared in their assessment of absolute stenosis as well as their ability to resolve different plaque morphologies.

Results

Lesions were found to have similar degrees of stenosis when utilizing CBCT-A compared with 3DRA, but both 3DRA and CBCT-A differed from DSA in their assessment of the absolute degree of stenosis. CBCT-A provided the most detailed resolution of plaque morphology, identifying a new plaque characteristic in 61% of patients (n = 11) when compared with DSA and 50% (n = 9) when compared with 3DRA. CBCT-A identified all lesion characteristics visualized on DSA and 3DRA.

Conclusions

CBCT-A provides detailed spatial resolution of plaque morphology and may add to DSA and 3DRA in the evaluation of ICAD. Further prospective study is warranted to determine any benefit CBCTA-A may provide in clinical decision making and risk stratification over existing conventional imaging modalities.