The Frequency and Determinants of Calcification in Intracranial Arteries in Chinese Patients Who Underwent Computed Tomography Examinations

Effect of Drug-Coated Balloon Versus Stent Angioplasty in Patients With Symptomatic Intracranial Atherosclerotic Stenosis

BACKGROUND AND OBJECTIVES

Drug-coated balloons (DCBs) have exhibited promising results in coronary and peripheral artery diseases, but conclusive evidence is lacking in intracranial vasculature. We assessed the safety and efficacy of DCBs vs stent angioplasty for symptomatic intracranial atherosclerotic stenosis (sICAS) and initially identified patients who might have benefited most from DCB treatment.

METHODS

A single-center, retrospective cohort study was conducted from June 2021 to May 2022 with 154 patients with sICAS divided into 2 treatment groups: a DCB group (with or without remedial stenting, n = 47) and a stent group (n = 107). The treatment outcomes were compared using 1:2 propensity score matching. The primary safety end point was perioperative stroke or mortality, and the primary efficacy end point was the rate of target vessel restenosis at 12 months. The degree of luminal change was analyzed as a subgroup, defined as the difference between the degree of stenosis at follow-up and immediately after intervention.

RESULTS

One hundred eighteen patients were enrolled using propensity score matching, with 43 patients in the DCB group and 75 in the stent group. The incidence of perioperative adverse events was 2.3% in the DCB group and 8.0% in the stent group (P = .420). At a median follow-up of 12 months, the incidence of restenosis (11.9% [5/43] vs 28.0% [21/75], P = .045) and the median degree of stenosis (30% [20%, 44%] vs 30% [30%, 70%], P = .009, CI [0-0.01, 0.2]) were significantly lower in the DCB group than in the stent group. DCB angioplasty effectively prevented adverse events in the target vessel area and significantly reduced the degree of luminal change in the M1 segment of the middle cerebral artery (0 [0, 15%] vs 10% [0, 50%], P = .016).

CONCLUSION

DCB angioplasty might be a safe and effective alternative to stent angioplasty to treat sICAS, particularly among patients with M1 segment of the middle cerebral artery stenosis.

Dual-Energy Computed Tomography Virtual Noncalcium Imaging of Intracranial Arteries in Acute Ischemic Stroke: Differentiation Between Acute Thrombus and Calcification

OBJECTIVE

Hyperdense artery sign (HAS) on noncontrast brain computed tomography (CT) indicates an acute thrombus within the cerebral artery. It is a valuable imaging biomarker for diagnosing large-vessel occlusion; however, its identification may be challenging with the presence of vascular calcification. Dual-energy CT virtual noncalcium (VNCa) imaging using a 3-material decomposition algorithm is helpful for differentiating between calcification and hemorrhage. This study aimed to clarify the potential of VNCa imaging for differentiating HAS from vascular calcification.

METHODS

Patients with acute ischemic stroke and large-vessel occlusion identified on MR angiography, who also underwent noncontrast dual-energy CT, were included. The 80 kV/Sn 140 kV mixed images, with a weighting factor of 0.4, were considered 120 kVp-equivalent images. Postprocessing using a 3-material decomposition algorithm to differentiate between calcium (Ca), cerebrospinal fluid, and hemorrhage was performed via a commercially available 3-dimensional workstation. A mixed image, VNCa image, color-coded Ca image, and color-coded Ca image with VNCa image overlay (color-coded Ca-overlay image) were obtained, and axial reconstruction with a 1-mm slice thickness was performed for each image type. Two experienced neuroradiologists conducted imaging evaluations in consensus.

RESULTS

Thirty-four patients (mean age, 76.0 years; 21 male and 13 female patients) were included. The mixed and VNCa images revealed an HAS (indicating an acute clot) corresponding to the large-vessel occlusion site in 30 patients. Among them, the VNCa and color-coded Ca-overlay images enabled clear differentiation between the acute thrombus and adjacent vessel wall calcification in 5 patients. Among the other 4 patients, the VNCa, Ca-overlay, and Ca images identified calcified cerebral emboli in the M1 segment in 1 patient. For the other 3 patients, no high attenuation corresponding to magnetic resonance angiography findings was observed in any of the mixed, VNCa, Ca-overlay, or Ca images.

CONCLUSIONS

VNCa and color-coded Ca-overlay images obtained via dual-energy brain CT enabled differentiation of acute thrombus from vessel wall calcification and calcified cerebral emboli in patients with acute ischemic stroke.

Imaging of intracranial arterial disease: a comparison between MRI and unenhanced CT

Background and purpose

Arterial calcifications on unenhanced CT scans and vessel wall lesions on MRI are often used interchangeably to portray intracranial arterial disease. However, the extent of pathology depicted with each technique is unclear. We investigated the presence and distribution of these two imaging findings in patients with a history of cerebrovascular disease.

Materials and methods

We analyzed CT and MRI data from 78 patients admitted for stroke or TIA at our institution. Vessel wall lesions were assessed on 7 T MRI sequences, while arterial calcifications were assessed on CT scans. The number of vessel wall lesions, severity of intracranial internal carotid artery (iICA) calcifications, and overall presence and distribution of the two imaging findings were visually assessed in the intracranial arteries.

Results

At least one vessel wall lesion or arterial calcification was assessed in 69 (88%) patients. Only the iICA and vertebral arteries (VA) showed a substantial number of both calcifications and vessel wall lesions. The other vessels showed almost exclusively vessel wall lesions. The number of vessel wall lesions was associated with the severity of iICA calcification (p = 0.013).

Conclusions

The number of vessel wall lesions increases with the severity of iICA calcifications. Nonetheless, the distribution of vessel wall lesions on MRI and arterial calcifications on CT shows remarkable differences. These findings support the need for a combined approach to examine intracranial arterial disease.

Intracranial Carotid Artery Calcification Subtype in Patients with Anterior Circulation Acute Ischemic Stroke Undergoing Intravenous Thrombolysis

Background and Aim

The aim of this study was to investigate the potential value of intracranial carotid artery calcification (ICAC) in therapeutic efficacy and functional outcomes in patients with anterior circulation acute ischemic stroke (AIS) undergoing intravenous thrombolysis.

Materials and Methods

A total of 207 patients with anterior circulation AIS who underwent intravenous thrombolysis were enrolled in this retrospective study. We divided them into three groups according to thin-slice head noncontrast computed tomography as follows: no ICAC, medial ICAC, and intimal ICAC. The differences in risk factors of different ICAC subtypes were compared, and the effect of ICAC subtype on hemorrhage transformation (HT) after intravenous thrombolysis was also evaluated. Functional outcomes were assessed at 90 days using the modified Rankin Scale.

Results

Compared to the no and intimal ICAC, patients with the medial ICAC were older and more likely to have diabetes mellitus, hyperlipidemia, previous stroke, and atrial fibrillation. Moreover, the medial ICAC group had a high baseline National Institute of Health Stroke Scale (NIHSS) score and a high incidence of HT. Multivariate logistic regression analysis showed that baseline NIHSS score (odds ratio [OR]: 1.121, 95% confidence interval [CI]: 1.027-1.224) was independently associated with HT. Medial ICAC (OR: 7.418, 95% CI: 1.190-46.231) and baseline NIHSS score (OR: 1.141, 95% CI: 1.042-1.250) were independent risk factors of poor functional outcome at 90 days.

Conclusions

Medial ICAC could be a new imaging biomarker for predicting functional outcomes in patients with anterior circulation AIS undergoing intravenous thrombolysis. Medial ICAC and baseline NIHSS score were independently associated with poor prognosis at 90 days.

Predictors of intraoperative intracranial aneurysm rupture in patients with subarachnoid hemorrhage: a retrospective analysis

PURPOSE

Intraoperative cerebral aneurysm rupture (IOR) is a common phenomenon with a frequency of around 19%. Research regarding IOR lacks an analysis of its predictors.

METHODS

We retrospectively examined all saccular aneurysms, in 198 patients with subarachnoid hemorrhage, surgically treated from 2013 to 2019. Operative reports, patient histories, blood test results, discharge summaries, and radiological data were reviewed. IOR was defined as any bleeding from the aneurysm during surgery, preceding putting a clip on its neck, regardless of how trivial.

RESULTS

The frequency of IOR was 20.20%. Patients with IOR had higher aneurysm dome size (9.43 ± 8.39 mm vs. 4.96 ± 2.57 mm; p < 0.01). The presence of blood clot on the aneurysm dome was significantly associated with IOR (12.50% vs. 2.53%; p < 0.01). We also associated lamina terminalis fenestration during surgery (7.50% vs. 21.52%; p = 0.04) and multiple aneurysms (5.00% vs. 18.35%; p = 0.038) with a lower risk of IOR. Glucose blood levels were also elevated in patients with IOR (7.47 ± 2.78 mmol/l vs. 6.90 ± 2.22 mmol/l; p = 0.04). Multivariate analysis associated that urea blood levels (OR 0.55, 0.33 to 0.81, p < 0.01) and multiple aneurysms (OR 0.04, 0.00 to 0.37, p = 0.014) were protective factors against the occurrence of IOR.

CONCLUSION

Large dome size of an aneurysm, a blood clot on the aneurysm dome and elevated glucose blood levels can be IOR predictive. Lamina terminalis fenestration, the appearance of multiple aneurysms, and high urea blood levels may be associated with a lower risk of such an event.

Brachial-ankle pulse wave velocity is associated with intracranial artery calcification in acute stroke patients

BACKGROUND

Intracranial artery calcification (IAC) is closely associated with cerebrovascular disease. Brachial-ankle pulse wave velocity (baPWV) is a noninvasive method for estimating arterial stiffness, which reflects the stiffness of peripheral arteries. This study aimed to examine the association of baPWV with the presence and degree of IAC in patients with acute ischemic stroke.

METHODS

A total of 143 ischemic stroke subjects were recruited. A head computed tomography (CT) scan was used to assess the presence and severity of IAC. The oscillometric method was used to simultaneously measure bilateral brachial and posterior tibial arterial pulse waveforms and arterial BP. Multiple logistic regression analysis was used to identify the independent relationship between baPWV and IAC.

RESULTS

143 subjects were included in this study. The demographic and clinical characteristics of the study population were classified according to the baPWV quartile. A higher prevalence of IAC was noted across increasing baPWV quartiles (Q1: 53 %, Q2: 69 %, Q3: 86 %, Q4: 94 %, P < 0.001). IAC scores were also increased with elevated ccPWV values (1.60 ± 1.71; 2.56 ± 1.99; 3.44 ± 1.91; 4.64 ± 1.58. P < 0.001). After an additional adjustment for age and hypertension, the odds ratio (95 % confidence interval) for the IAC scores was 1.61 (1.06-2.45; P = 0.025) in the top quartile of baPWV compared with those in the lowest quartile.

CONCLUSIONS

Arterial stiffness as defined by baPWV was positively associated with the degree of IAC in patients with acute ischemic stroke, suggesting the severity of IAC may also be a marker of peripheral or systemic arterial stiffness.

Automated Intracranial Clot Detection: A Promising Tool for Vascular Occlusion Detection in Non-Enhanced CT

(1) Background: to test the diagnostic performance of a fully convolutional neural network-based software prototype for clot detection in intracranial arteries using non-enhanced computed tomography (NECT) imaging data. (2) Methods: we retrospectively identified 85 patients with stroke imaging and one intracranial vessel occlusion. An automated clot detection prototype computed clot location, clot length, and clot volume in NECT scans. Clot detection rates were compared to the visual assessment of the hyperdense artery sign by two neuroradiologists. CT angiography (CTA) was used as the ground truth. Additionally, NIHSS, ASPECTS, type of therapy, and TOAST were registered to assess the relationship between clinical parameters, image results, and chosen therapy. (3) Results: the overall detection rate of the software was 66%, while the human readers had lower rates of 46% and 24%, respectively. Clot detection rates of the automated software were best in the proximal middle cerebral artery (MCA) and the intracranial carotid artery (ICA) with 88-92% followed by the more distal MCA and basilar artery with 67-69%. There was a high correlation between greater clot length and interventional thrombectomy and between smaller clot length and rather conservative treatment. (4) Conclusions: the automated clot detection prototype has the potential to detect intracranial arterial thromboembolism in NECT images, particularly in the ICA and MCA. Thus, it could support radiologists in emergency settings to speed up the diagnosis of acute ischemic stroke, especially in settings where CTA is not available.

Aortic Stiffness Is Independently Associated with Intracranial Carotid Artery Calcification in Patients with Ischemic Stroke

INTRODUCTION

Intracranial carotid artery calcification (ICAC), as a strong contributor to the occurrence of ischemic stroke, might be present in the medial or intimal arterial layer. Traditional cardiovascular risk factors (CVRFs) are associated with ICAC; however, its association with new markers of vascular function is less understood. The paper aimed to evaluate the relationship between carotid-femoral pulse wave velocity (CF-PWV) and ICAC subtypes.

METHODS

We enrolled 65 patients with ischemic stroke. CF-PWV, systolic, diastolic, mean blood pressure, and pulse pressure were measured within 6 ± 2 days after stroke onset, and CT was performed within 24 h. ICAC on the stroke site was classified by two methods: volume and score based. Tertiles of ICAC volume were determined, and low-grade ICAC (T1) was regarded as a reference. According to the score-based method, (dominant) medial and (dominant) intimal ICAC subtypes were determined. Data were analyzed with multivariate logistic regression.

RESULTS

Medial and intimal ICAC subtypes were found in 34 (52%) and 24 (37%) patients, respectively. In 11% of patients, no ICAC calcifications were found. CF-PWV was higher in patients with high-grade ICAC (OR = 1.56, 95% CI = 1.03-2.35, p = 0.035). CF-PWV was higher in patients with the medial ICAC subtype (OR = 1.60, 95% CI = 1.00-2.55, p = 0.049) after adjustment for traditional CVRFs.

CONCLUSION

Our study demonstrates that among patients with ischemic stroke, aortic stiffness is independently associated with ICAC and that medial ICAC, compared with intimal ICAC, is accompanied by more advanced aortic stiffness.

Cerebral Arterial Stiffness as Measured Based on the Pulse Wave Velocity is Associated With Intracranial Artery Calcification in Patients With Acute Stroke

BACKGROUND AND PURPOSE

By measuring a newly defined parameter, the carotid-cerebral pulse wave velocity (ccPWV), this study aimed to determine the association of intracranial artery calcification (IAC) with arterial stiffness as reflected by the pulse wave velocity between the carotid and middle cerebral arteries using transcranial Doppler sonography in patients with acute stroke.

METHODS

We recruited 146 patients with ischemic stroke from our stroke center. Computed tomography of the head was used to assess the presence and severity of IAC. Arterial stiffness was evaluated using ccPWV. Data are presented as quartiles of ccPWV. A multivariable logistic regression model was used to assess the independent relationship between ccPWV and IAC.

RESULTS

The IAC prevalence increased with the ccPWV quartile, being 54%, 76%, 83%, and 89% for quartiles 1, 2, 3, and 4, respectively (p<0.001) as did IAC scores, with median [interquartile range] values of 0 [0-2], 3 [2-4], 4 [2-5], and 5 [4-6], respectively (p<0.001). After additionally adjusting for age and hypertension, a significant correlation was only found between quartiles 3 and 4 of ccPWV and IAC scores. The odds ratio (95% confidence interval) for the IAC scores was 1.78 (1.28-2.50) (p=0.001) in quartile 4 of ccPWV and 1.45 (1.07-1.95) (p=0.015) in quartile 3 compared with quartile 1.

CONCLUSIONS

We found that in patients with acute ischemic stroke, ccPWV was positively related to the degree of IAC. Future longitudinal cohort studies may help to identify the potential role of IAC in the progression of cerebral arterial stiffness.

Feasibility and intra-and interobserver reproducibility of quantitative susceptibility mapping with radiomic features for intracranial dissecting intramural hematomas and atherosclerotic calcifications

Quantitative susceptibility mapping (QSM) for 61 patients with dissecting intramural hematomas (n = 36) or atherosclerotic calcifications (n = 25) in intracranial vertebral arteries were collected to assess intra- and interobserver reproducibility in a 3.0-T MR system between January 2015 and December 2017. Two independent observers each segmented regions of interest for lesions twice. The reproducibility was evaluated using intra-class correlation coefficients (ICC) and within-subject coefficients of variation (wCV) for means and concordance correlation coefficients (CCC) and ICC for radiomic features (CCC and ICC > 0.85) were used. Mean QSM values were 0.277 ± 0.092 ppm for dissecting intramural hematomas and - 0.208 ± 0.078 ppm for atherosclerotic calcifications. ICCs and wCVs were 0.885-0.969 and 6.5-13.7% in atherosclerotic calcifications and 0.712-0.865 and 12.4-18.7% in dissecting intramural hematomas, respectively. A total of 9 and 19 reproducible radiomic features were observed in dissecting intramural hematomas and atherosclerotic calcifications, respectively. QSM measurements in dissecting intramural hematomas and atherosclerotic calcifications were feasible and reproducible between intra- and interobserver comparisons, and some reproducible radiomic features were demonstrated.

Intracranial artery calcification as an independent predictor of ischemic stroke: a systematic review and a meta-analysis

BACKGROUND AND PURPOSE

The association between intracranial artery calcification (IAC) and the risk of ischemic stroke occurrence or poor prognosis had not yet been fully understood. In this study, we conducted a meta-analysis of existing studies aimed to assess whether IAC can be used to predict future ischemic stroke and post-stroke mortality.

METHODS

Medline, Cochrane, Web of Science and Google Scholar databases were searched up to June 30, 2022. Studies were included if they reported risk ratio (RR) or odds ratios (OR) and corresponding 95% confidence intervals (CI) of stroke concerning the presence of IAC. Random or fixed effects model meta-analyses were performed. Meta-analysis was conducted by using Stata version 16.0.

RESULTS

Twelve studies involving 9346 participants were included. Compared with those without IAC, patients with IAC had a higher risk of stroke occurrence (adjusted OR 1.62, 95% CI 1.18-2.23, P = 0.001) and stroke recurrence (adjusted OR 1.77, 95% CI 1.25-2.51, P = 0.003). However, we did not find a significant correlation between IAC and post-stroke mortality (pooled OR 1.12, 95% CI 0.80-1.56, P = 0.504).

CONCLUSIONS

Our meta-analysis demonstrated that the presence of IAC was identified as an independent risk factor for ischemic stroke occurrence and recurrence but is not a predictor of post-stroke mortality.

Apolipoprotein E genotypes were not associated with intracranial atherosclerosis: a population-based autopsy study

BACKGROUND

Apolipoprotein E gene (APOE) ε4 allele is associated with a higher risk of carotid atherosclerosis, but less is known about the association of APOE with intracranial atherosclerotic disease (IAD). We aimed to investigate the association of APOE alleles with IAD in a cross-sectional autopsy study.

METHODS

We measured the stenosis in the 12 arteries of the Circle of Willis using postmortem morphometric measurements. The APOE polymorphism was determined by real-time polymerase chain reaction. We assessed the association between APOE polymorphism and IAD using regression models adjusted for sociodemographic and clinical variables. We also verified the modifier effect of age, sex, and race on this association. We stratified the analysis by age group to investigate the possibility of attrition bias.

RESULTS

In 400 participants (mean age=73.2±12.3 years old, 51% female, and 64% White), IAD was evaluated in 4,504 artery segments. APOE-ε4 was not associated with IAD nor with the number of artery stenosis compared to non-APOE-ε4 carriers. Sociodemographic variables did not modify this relationship. Among participants older than 70 years, there was a trend towards an association between APOE allele ε4 and a lower stenosis index in the middle cerebral artery, suggesting attrition bias related to the APOE-ε4 effect on mortality.

CONCLUSIONS

APOE alleles were not associated with IAD in this population-based autopsy study. Lower stenosis in older participants suggests the possibility of attrition bias.

Serum biomarkers for arterial calcification in humans: A systematic review

Aim

To clarify the role of mediators of ectopic mineralization as biomarkers for arterial calcifications.

Methods

MEDLINE and Embase were searched for relevant literature, until January 4th 2022. The investigated biomarkers were: calcium, phosphate, parathyroid hormone, vitamin D, pyrophosphate, osteoprotegerin, receptor activator of nuclear factor-kappa B ligand (RANKL), fibroblast growth factor-23 (FGF-23), Klotho, osteopontin, osteocalcin, Matrix Gla protein (MGP) and its inactive forms and vitamin K. Studies solely performed in patients with kidney insufficiency or diabetes mellitus were excluded.

Results

After screening of 8985 articles, a total of 129 articles were included in this systematic review. For all biomarkers included in this review, the results were variable and more than half of the studies for each specific biomarker had a non-significant result. Also, the overall quality of the included studies was low, partly as a result of the mostly cross-sectional study designs. The largest body of evidence is available for phosphate, osteopontin and FGF-23, as a little over half of the studies showed a significant, positive association. Firm statements for these biomarkers cannot be drawn, as the number of studies was limited and hampered by residual confounding or had non-significant results. The associations of the other mediators of ectopic mineralization with arterial calcifications were not clear.

Conclusion

Associations between biomarkers of ectopic mineralization and arterial calcification are variable in the published literature. Future longitudinal studies differentiating medial and intimal calcification could add to the knowledge of biomarkers and mechanisms of arterial calcifications.

•

We researched the association between biomarkers and arterial calcifications.

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This review focused on biomarkers of bone metabolism and Matrix Gla protein.

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Associations between biomarkers and arterial calcification are variable.

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Future studies should differentiate between medial and intimal calcifications.

Intracranial Arterial Calcifications: Potential Biomarkers of Stroke Risk and Outcome

Intracranial artery calcifications (IAC), a common and easily identifiable finding on computed tomorgraphy angiography (CTA), has gained recognition as a possible risk factor for ischemic stroke. While atherosclerosis of intracranial arteries is believed to be a mechanism that commonly contributes to ischemic stroke, and coronary artery calcification is well-established as a predictor of both myocardial infarction (MI) and ischemic stroke risk, IAC is not currently used as a prognostic tool for stroke risk or recurrence. This review examines the pathophysiology and prevalence of IAC, and current evidence suggesting that IAC may be a useful tool for prediction of stroke incidence, recurrence, and response to acute ischemic stroke therapy.

Silent brain infarction is associated with carotid siphon calcification in ischemic stroke patients

BACKGROUND

Silent brain infarction (SBI) had a higher prevalence in ischemic stroke patients than healthy population. Intracranial artery calcification, as the important component of atherosclerosis, is a known risk factor of ischemic stroke. Whether it is also the risk factor of SBI is uncertain. We aimed to assess the association between SBI and carotid siphon calcification (CSC) in ischemic stroke patients.

METHODS

We retrospectively collected consecutive data of acute ischemic stroke patients with and without SBI by Magnetic Resonance Imaging (MRI) and calcification using non-contrast Computerized Tomography (NCCT). We used a histopathologically validated method to score the circularity, thickness, and morphology of calcification. Clinical characteristics, prevalence and pattern (intimal and medial) of CSC were compared between patients with and without SBI. The association of CSC and SBI was investigated by logistic regression analysis.

RESULTS

Totally, 303 acute ischemic stroke patients were enrolled, of whom 260 (85.8%) had CSC. Patients with SBI were older (64.5 ± 10.4 years vs. 61.3 ± 12.1 years, P = 0.032), had a higher proportion of hypertension (77.5% vs. 65.7%, P = 0.035). Of the 260 CSC patients, there's no significant difference except for hyperlipidemia between patients with SBI and without SBI. The prevalence of intimal pattern of CSC was higher in those with SBI (adjusted odds ratio 2.42, 95% CI 1.219-4.794).

CONCLUSIONS

Patients with SBI at acute phase of ischemic stroke have more risk factors than mentioned previously. SBI associated with the intimal pattern of CSC which relate to the atherosclerosis process in symptomatic ischemic stroke patients.

Correlation Between Intracranial Carotid Artery Calcification and Prognosis of Acute Ischemic Stroke After Intravenous Thrombolysis

Objective

To investigate the correlation between prognosis and intracranial carotid artery calcification (ICAC) in patients with acute ischemic stroke (AIS) who receive intravenous thrombolysis (IVT).

Methods

A total of 156 AIS patients who received IVT from March 2019 to March 2020 were enrolled. The modified Woodcock visual score was used to evaluate ICAC in nonenhanced head CT scans. Patients were divided into high calcification burden (HCB; score ≥3) and low calcification burden (LCB; score <3) groups. Demographic, laboratory, imaging and clinical data were compared between the two groups, and whether HCB was a prognostic factor was evaluated.

Results

Compared with the LCB group, the HCB group had a higher incidence of atrial fibrillation (49.2 vs.22.1%, P < 0.001) and coronary heart disease (24.6 vs. 10.0%, P = 0.019) and higher serum homocysteine [15.31 (12.15, 17.50) vs. 14.40 (11.20, 16.20), P = 0.036] and hemoglobin A1c (6.93 ± 1.77 vs. 6.37 ± 0.74, P = 0.023) levels. Binary logistic regression analysis showed that atrial fibrillation (OR = 3.031, 95% CI: 1.312–7.006, P = 0.009) and HbA1c (OR = 1.488, 95% CI: 1.050–2.109, P = 0.026) were independent risk factors for ICAC. After adjusting for other risk factors, symptomatic-side and bilateral ICACs were independent risk factors for poor prognosis (OR = 1.969, 95% CI: 1.220–3.178, P = 0.006), (OR = 1.354, 95% CI: 1.065–1.722, P = 0.013) and mortality (OR = 4.245, 95% CI: 1.114–16.171, P = 0.034), (OR = 2.414, 95% CI = 1.152–5.060, P = 0.020) in patients with AIS who received IVT.

Conclusion

ICAC is closely related to the prognosis of acute ischemic stroke after intravenous thrombolysis.

Intracranial Arterial Calcification and Intracranial Atherosclerosis: Close but Different

Background and Purpose

Intracranial arterial calcification (IAC) may be present in the intimal or medial arterial layer. This study aimed to elucidate the link between the calcification and atherosclerotic disease in the intracranial vasculature.

Methods

Consecutive patients with acute ischemic stroke were included. Bilateral intracranial segment of the internal carotid artery, M1 segment of the middle cerebral artery, intracranial segment of the vertebral artery, and the basilar artery were visualized by the multi-detector computed tomography (CT) and vessel-wall magnetic resonance imaging (vwMRI) within 14 days after stroke onset. IAC was into the intimal or medial pattern. Subsequently, on the vwMRI, we assessed the luminal stenosis, eccentricity, plaque burden, and intraplaque hemorrhage (IPH) as markers of atherosclerosis at each IAC site.

Results

Among 69 patients with stroke, IAC was identified in 35% of (161/483) artery segments, of which 61.5% were predominantly intimal calcification and 38.5% were predominantly medial calcification. About 79.8% of intimal calcifications and 64.5% of medial calcifications co-existed with atherosclerotic plaques. Intimal calcification was associated with luminal stenosis (p = 0.003) caused by atherosclerotic lesions. Compared with the medial IAC, intimal IAC was more often accompanied by eccentric plaques (p = 0.02), larger plaque burden (p = 0.001), and IPH (p = 0.001).

Conclusion

Our multimodal imaging-based comparison study on intracranial arteriosclerosis demonstrated that intimal IAC, compared with medial IAC, was more often accompanied by the luminal stenosis, larger plaque burden, eccentricity, and IPH, providing strong evidence for clinical evaluation on the mechanism, risk, and prognosis of ischemic stroke.

Histology-Verified Intracranial Artery Calcification and Its Clinical Relevance With Cerebrovascular Disease

Intracranial artery calcification (IAC) was regarded as a proxy for intracranial atherosclerosis (ICAS). IAC could be easily detected on routine computer tomography (CT), which was neglected by clinicians in the previous years. The evolution of advanced imaging technologies, especially vessel wall scanning using high resolution-magnetic resonance imaging (HR-MRI), has aroused the interest of researchers to further explore the characteristics and clinical impacts of IAC. Recent histological evidence acquired from the human cerebral artery specimens demonstrated that IAC could mainly involve two layers: the intima and the media. Accumulating evidence from histological and clinical imaging studies verified that intimal calcification is more associated with ICAS, while medial calcification, especially the internal elastic lamina, contributes to arterial stiffness rather than ICAS. Considering the highly improved abilities of novel imaging technologies in differentiating intimal and medial calcification within the large intracranial arteries, this review aimed to describe the histological and imaging features of two types of IAC, as well as the risk factors, the hemodynamic influences, and other clinical impacts of IAC occurring in intimal or media layers.

High prevalence of middle cerebral artery calcification is associated with cardiovascular mortality in hemodialyzed patients: an overlooked part of arterial tree?

PURPOSE

We have analyzed markers of accelerated atherosclerosis like large artery stiffness, ankle-brachial index, carotid and vertebral duplex ultrasonography and their possible associations with the incidence of intracranial calcifications, clinical course of hemodialyzed patients, and cardiovascular mortality.

METHODS

A computed tomographic scan of the head was performed for any neurological indication on 100 hemodialyzed patients. Eleven intracranial arteries were analyzed for calcification score, while internal carotid arteries and vertebral arteries were excluded in cerebral artery calcification score. As a control group for assessing intracranial calcifications, we have analyzed computed tomographic scans from diabetic patients who had an acute stroke.

RESULTS

Deceased patients had significantly higher values of augmentation index and pulse wave velocity, lower ankle-brachial index, and higher internal carotid arteries peak systolic value than survived patients. Deceased patients had significantly higher number of calcified middle cerebral arteries as well as significantly higher intracranial artery calcification score and cerebral artery calcification score. Hemodialyzed patients had significantly higher both intracranial and cerebral artery calcification scores than diabetic control group. Age and calcified middle cerebral arteries had increased HR of 1.08 and 1.36 for cardiovascular mortality.

CONCLUSION

This study showed that large artery stiffness and not the presence of peripheral arterial disease or carotid artery stenosis have the prognostic role of middle cerebral arteries' calcifications and cardiovascular mortality in hemodialyzed patients. The presence of middle cerebral arteries' calcifications diagnosed by a non-invasive method should be considered a marker of middle-sized conduit arteries atherosclerosis, subclinical brain damage, and future fatal cardiovascular events.

Carotid Artery Calcification: What We Know So Far

Carotid artery calcification (CAC) is a well-known marker of atherosclerosis and is linked to a high rate of morbidity and mortality. CAC is divided into two types: intimal and medial calcifications, each with its own set of risk factors. Vascular calcification is now understood to be an active, enzymatically regulated process involving dystrophic calcification and endothelial dysfunction at an early stage. This causes a pathogenic inflammatory response, resulting in calcium phosphate deposition in the form of microcalcifications, which causes plaque formation, ultimately becoming unstable with sequelae of complications. If the inflammation goes away, hydroxyapatite crystal formation takes over, resulting in macro-calcifications that help to keep the plaque stable. As CAC can be asymptomatic, it is critical to identify it early using diagnostic imaging. The carotid artery calcification score is calculated using computed tomography angiography (CTA), which is a confirmatory test that enables the examination of plaque composition and computation of the carotid artery calcification score. Magnetic resonance angiography (MRA), which is sensitive as CTA, duplex ultrasound (DUS), positron emission tomography, and computed tomography (PET-CT) imaging with (18) F-Sodium Fluoride, and Optical Coherence Tomography (OCT) are some of the other diagnostic imaging modalities used. The current therapeutic method starts with the best medical care and is advised for all CAC patients. Carotid endarterectomy and carotid stenting are two treatment options that have mixed results in terms of effectiveness and safety. When patient age and anatomy, operator expertise, and surgical risk are all considered, the agreement is that both techniques are equally beneficial.

Association between Periodontitis and Carotid Artery Calcification: A Systematic Review and Meta-Analysis

Recent studies have supported the relationship between periodontitis and carotid artery calcification (CAC), but still uncertain. This systematic review is aimed at evaluating the association between periodontitis and CAC. The search was conducted in four electronic databases: PubMed, EMBASE, Web of Science, and The Cochrane Library, supplemented by checking references of included articles and related review articles. Eligibility assessment and data extraction were conducted independently. The quality assessment and publication bias analysis were performed. The association between periodontitis and CAC was presented in odd ratio (OR) with 95% confidence interval (CI). Additional outcomes included the percentage of alveolar bone loss in CAC versus non-CAC. Twelve studies were included, and 10 were performed quantity analysis. Periodontitis with secure definition (OR = 2.02, 95%CI = 1.18 − 3.45) and insecure definition (OR = 10.78, 95%CI = 4.41 − 26.34) was associated with CAC. And a higher average percentage of alveolar bone loss (weighted mean difference = 10.84%; 95%CI = 6.40 − 15.48) was also observed in CAC patients compared to non-CAC patients. No significant publication bias was found. The results of this systematic review and meta-analysis revealed a significant relationship between periodontitis and CAC.

Intracranial Arterial Calcification: Prevalence, Risk Factors, and Consequences: JACC Review Topic of the Week

Intracranial large and small arterial calcifications are a common incidental finding on computed tomography imaging in the general population. Here we provide an overview of the published reports on prevalence of intracranial arterial calcifications on computed tomography imaging and histopathology in relation to risk factors and clinical outcomes. We performed a systematic search in Medline, with a search filter using synonyms for computed tomography scanning, (histo)pathology, different intracranial arterial beds, and calcification. We found that intracranial calcifications are a frequent finding in all arterial beds with the highest prevalence in the intracranial internal carotid artery. In general, prevalence increases with age. Longitudinal studies on calcification progression and intervention studies are warranted to investigate the possible causal role of calcification on clinical outcomes. This might open up new therapeutic directions in stroke and dementia prevention and the maintenance of the healthy brain.

Understanding the Clinical Implications of Intracranial Arterial Calcification Using Brain CT and Vessel Wall Imaging

Background and Purpose: Intracranial arterial calcification (IAC) has been the focus of much attention by clinicians and researchers as an indicator of intracranial atherosclerosis, but correlations of IAC patterns (intimal or medial) with the presence of atherosclerotic plaques and plaque stability are still a matter of debate. Our study aimed to assess the associations of IAC patterns identified on computed tomography (CT) with the presence of plaque detected on vessel wall magnetic resonance imaging and plaque stability. Materials and Methods: Patients with stroke or transient ischemic attack and intracranial artery stenosis were recruited. IAC was detected and localized (intima or media) on non-contrast CT images. Intracranial atherosclerotic plaques were identified using vessel wall magnetic resonance imaging and matched to corresponding CT images. Associations between IAC patterns and culprit atherosclerotic plaques were assessed by using multivariate regression. Results: Seventy-five patients (mean age, 63.4 ± 11.6 years; males, 46) were included. Two hundred and twenty-one segments with IAC were identified on CT in 66 patients, including 86 (38.9%) predominantly intimal calcifications and 135 (61.1%) predominantly medial calcifications. A total of 72.0% of intimal calcifications coexisted with atherosclerotic plaques, whereas only 10.2% of medial calcifications coexisted with plaques. Intimal calcification was more commonly shown in non-culprit plaques than culprit plaques (25.9 vs. 9.4%, P = 0.008). The multivariate mixed logistic regression adjusted for the degree of stenosis showed that intimal calcification was significantly associated with non-culprit plaques (OR, 2.971; 95% CI, 1.036-8.517; P = 0.043). Conclusion: Our findings suggest that intimal calcification may indicate the existence of a stable form of atherosclerotic plaque, but plaques can exist in the absence of intimal calcification especially in the middle cerebral artery.

Intracranial Arterial Calcification Relates to Long-Term Risk of Recurrent Stroke and Post-stroke Mortality

Background: Intracranial arterial calcification (IAC) is highly prevalent in ischemic stroke patients. However, data on the association of IAC with stroke recurrence and mortality remains limited. We examined the effect of IAC on the long-term recurrence of stroke and the risk of post-stroke mortality.

Methods: Using a prospective stroke registry, we recruited 694 patients (mean age 71.6 ± 12.4; male sex 50.3%) since December 2004. IAC was visualized using the computed tomography exam that was made at hospital admission and was quantified with the Agatston method. All patients were regularly followed up till July 2016. The impacts of IAC on stroke recurrence and mortality were assessed using Cox-regression models with adjustments for age, sex, and relevant cardiovascular risk factors.

Results: During a median follow-up period of 8.8 years, 156 patients (22.5%) suffered a recurrent stroke and 84 died (12.1%). We found that a higher IAC Agatston score related to a higher risk of stroke recurrence (HR per 1-SD increase in IAC: 1.30; 95% CI, 1.08–1.56, p = 0.005) and a higher risk of post-stroke mortality (HR per 1-SD increase, 1.44; 95% CI, 1.06–1.96, p = 0.019). After investigating etiology-specific risks of stroke-recurrence, we found that a higher IAC Agatston score specifically associated with small-vessel occlusive stroke.

Conclusions: IAC is a strong risk factor for recurrent stroke and post-stroke mortality. Among stroke subtypes, IAC relates to higher risk of stroke recurrence among patients with small-vessel disease, which indicates chronic calcification detected in large cerebral arteries may have potential effects on the cerebrovascular beds extending to small vessels.

Prevalence and Correlates of Intracranial Atherosclerotic Disease Among Community-Dwelling Older Adults of Amerindian Ancestry. The Three Villages Study

BACKGROUND

Knowledge on the prevalence and correlates of intracranial atherosclerotic disease (ICAD) is limited. We aimed to assess prevalence, clinical and neuroimaging correlates of ICAD in a cohort of older adults of Amerindian ancestry.

METHODS

The study included 581 community-dwellers aged ≥60 years (mean age 71 ± 8.4 years; 57% women) living in rural Ecuadorian villages. ICAD was identified by means of CT determinations of carotid siphon calcifications (CSC) or MRA findings of significant stenosis of intracranial arteries. Fully-adjusted logistic regression models were fitted with biomarkers of ICAD as the dependent variables.

RESULTS

A total of 205 (35%) of 581 participants had ICAD, including 185 with high calcium content in the carotid siphons and 40 with significant stenosis of at least one intracranial artery (20 subjects had both biomarkers). Increasing age, high fasting blood glucose, >10 enlarged basal ganglia-perivascular spaces and non-lacunar strokes were associated with high calcium content in the carotid siphons. In contrast, male gender, moderate-to-severe white matter hyperintensities, lacunar and non-lacunar strokes were associated with significant stenosis of intracranial arteries. Stroke was more common among subjects with any biomarker of ICAD than in those with no biomarkers (29% versus 9%, p < 0.001). Significant stenosis of intracranial arteries was more often associated with stroke than high calcium content in the carotid siphons, suggesting that CSC are more likely an ICAD biomarker than causally related to stroke.

CONCLUSIONS

ICAD prevalence in Amerindians is high, and is significantly associated with stroke. CSC and significant stenosis of intracranial arteries may represent different phenotypes of ICAD.

Intracranial Calcification is Predictive for Hemorrhagic Transformation and Prognosis After Intravenous Thrombolysis in Non-Cardioembolic Stroke Patients

Aim: Hemorrhagic transformation is the major complication of intravenous thrombolysis. Calcification is used widely as an imaging indicator of atherosclerotic burden and cerebrovascular function. The relationship between intracranial calcification and hemorrhagic transformation has not been explored fully. We aimed to identify and quantify calcification in the main cerebral vessels to investigate the correlations between quantitative calcification parameters, hemorrhagic transformation, and prognosis.

Methods: Acute, non-cardiogenic, ischemic stroke patients with anterior circulation who received intravenous thrombolysis therapy in the First Hospital of Jilin University were retrospectively and consecutively included. All included patients underwent a baseline CT before intravenous thrombolysis and a follow-up CT at 24 hours. A third-party software, ITK-SNAP, was used to segment and measure the calcification volume. A vascular nonbone component with a CT value > 130 HU was considered calcified. Hemorrhagic transformation was determined based on the ECASS II classification criteria.

Results: The study included 242 patients, 214 of whom were identified as having calcification. Thirty-one patients developed hemorrhagic transformation. The calcification volume on the lesion side (0.1ml) was associated with hemorrhagic transformation (p = 0.004, OR= 1.504, 95% CI: 1.140–1.985). Ninety-six patients had poor prognoses. The poor prognosis group had more calcified vessels than the good prognosis group (p = 0.014, OR= 1.477, 95% CI: 1.083–2.015).

Conclusions: The arterial calcification volume on the lesion side is associated with hemorrhagic transformation after thrombolysis. The higher the number of calcified vessels, the greater the risk of poor prognosis.

Small dense low-density lipoprotein cholesterol is strongly associated with NIHSS score and intracranial arterial calcification in acute ischemic stroke subjects

Intracranial artery calcification (IAC) is an important risk factor for cerebral infarction and a key biomarker for intracranial artery stenosis. Small dense low-density lipoprotein cholesterol (sd-LDL-c) was independently associated with increased cardiovascular events and coronary calcification. Our study assessed whether sd-LDL-c is an independent factor for IAC in acute ischemic stroke (AIS) patients. This cross-sectional study involved a total of 754 patients with AIS (mean age: 65 ± 13.2 years). All the patients had received brain computed tomography angiography (CTA) examination to evaluate IAC. Serum sd-LDL-c levels and other biochemical parameters were analyzed. Admission NIHSS score and mRS score at discharge were collected. After 60-days 85 patients died during hospitalization and follow-up. Partial correlation analysis showed that serum sd-LDL-c levels were associated with admission NIHSS score and IAC score after adjusted age and gender. Logistic regression analysis showed that serum sd-LDL-c levels independently predicted NIHSS scores (β = 1.537, 95%CI: 0.134-2.878, p = 0.042) and IAC scores (β = 1.355, 95%CI: 0.319-2.446, p = 0.015). The average level of sd-LDL-c in patients who died was also significantly increased compared to survival patients (1.04 ± 0.59 vs 0.88 ± 0.44 mmol/L, p = 0.017). However, multivariate logistic regression analysis showed serum sd-LDL-c levels could not predict all-cause mortality and prognosis in AIS patients. Our study found that sd-LDL-c as a strong atherogenic lipid particle can independently predict admission NIHSS scores and the severity of cerebral artery calcification in AIS patients. However, its prognostic value in AIS patients still needs further study in the future.

Risk factors for calcification of the vertebrobasilar arteries in cardiovascular patients referred for a head CT, the SMART study

BACKGROUND AND PURPOSE

Vertebrobasilar artery calcification (VBAC) has been associated with increased stroke occurrence. Little is known on VBAC risk factors, especially for patients with cardiovascular disease. We aimed to assess risk factors associated with VBAC in a cohort of cardiovascular patients referred for a head computed tomography (CT) scan.

MATERIALS AND METHODS

All patients who underwent a clinically indicated, unenhanced, thin slice head CT 6 months before or after inclusion in the SMART study were included. CTs were assessed for presence of VBAC (dichotomously). Relative risks of the associations of age, sex, diabetes mellitus (DM), obesity, body mass index, estimated glomerular filtration rate, hypertension, hyperlipidemia, use of lipid lowering medication, smoking status, high sensitivity C-reactive protein, ankle-brachial index (ABI; ≤0.90, ≥1.30, continuous), internal carotid artery stenosis ≥70%, and carotid intima-media thickness (IMT) with VBAC were estimated using Poisson regression analysis with robust standard errors, adjusted for age and sex.

RESULTS

Of the 471 patients included (57% male, median age 58 [interquartile range 47-63]), 117 (24.8%) showed VBAC. Presence of VBAC was associated with older age (RR per 10 years=1.70 [95%CI 1.46-1.99]), DM (RR=1.45 [95%CI 1.03-2.06]), obesity (RR=1.53 [95%CI 1.10-2.12]), ABI ≤0.90 (RR=1.57 [95%CI 1.02-2.41]), and an increased carotid IMT (RR=2.60 per mm [95%CI 1.20-5.62]). Other measurements were not associated with VBAC.

CONCLUSIONS

We identified several markers associated with VBAC in patients with cardiovascular disease referred for a head CT. Future investigation into the relationship between VBAC and stroke is warranted to determine the potential of VBAC in stroke prevention.

Vitamin K Antagonist Use and Risk for Intracranial Carotid Artery Calcification in Patients With Intracerebral Hemorrhage

Background: Intracranial carotid artery calcification (ICAC) on computed tomography (CT) is a marker of atherosclerosis and an independent predictor of vascular events including stroke. While vitamin K antagonists (VKAs) are used to prevent embolic stroke, they have been shown to increase levels of both coronary and extracoronary artery calcification. This has not been studied for (intracranial) carotid arteries. The aim of this study is to investigate the association between VKA use and degree of ICAC. We tested our hypothesis in a cohort of patients with nontraumatic intracerebral hemorrhage (ICH) of which a substantial part used VKAs.

Materials and Methods: We retrospectively semiquantified ICAC on brain unenhanced CT of consecutive adult patients with nontraumatic ICH. Assessment was performed blinded to clinical characteristics and status of VKA use. We used a 5-point visual scale and dichotomized degree of ICAC in low and high degree. Patient demographics, VKA use, duration of VKA treatment, as well as known risk factors for intracranial calcification were collected. Univariable and multivariable logistic regression analyses were performed to investigate the association between ICAC and VKA use.

Results: Three hundred and seventy-six nontraumatic ICH patients were included of whom 77 were using VKAs (20.5%) with a median treatment duration of 35 months. Any degree of ICAC was detected in 289 patients (76.9%). Univariable analysis showed that a high degree of ICAC was significantly associated with older age [odds ratio (OR), 1.06, 95% confidence interval (CI), 1.03–1.08], hypertension (OR, 2.14; 95% CI, 1.27–3.62), diabetes mellitus (OR, 2.38; 95% CI, 1.27–4.49), and the use of VKAs (OR, 1.84; 95% CI, 1.06–3.20). In multivariable regression analysis, only older age was significantly associated with a higher degree of ICAC (OR, 1.05; 95% CI, 1.02–1.08), while VKA use was not (OR, 1.22; 95% CI, 0.67–2.24).

Conclusions: Our findings do not support VKA use as an independent risk factor for higher ICAC degree in patients with ICH. We could not confirm the concerns about VKA use and intracranial carotid vascular calcification. We suggest further research in other cohorts with VKA users such as patients with ischemic stroke and atrial fibrillation.

Postmortem Study Exploring Distribution and Patterns of Intracranial Artery Calcification

Background and Purpose- Intracranial artery calcification detected by computed tomography is associated with ischemic stroke as an indicator of intracranial atherosclerosis. However, little is known about its histopathology. This study aimed to explore the intracranial calcification patterns and their associations with atherosclerotic plaques. Methods- We recruited 32 adult autopsy cases to assess the calcification patterns and distributions in the middle cerebral artery, vertebral artery, and basilar artery. The relationships of calcification patterns with plaque phenotype and luminal stenosis were evaluated. The calcification patterns on computed tomography were correlated with that on histology. Results- Visible calcifications were detected within 37 (39%) segments, including 25 segments with intimal calcification, 6 segments with internal elastic lamina calcification, 3 segments with adventitial calcification, and 3 segments with concurrent calcification. Calcification occurred more often in the vertebral artery (51%), followed by the middle cerebral artery (35%) and basilar artery (14%; P<0.01 for vertebral artery versus basilar artery). Internal elastic lamina calcification was predominantly detected in the vertebral artery (7/8, 88%). All of the 27 (100%) intimal calcifications were present in the progressive atherosclerotic lesions ( P<0.001), whereas only 3/8 (38%) internal elastic lamina calcifications and 4/6 (67%) adventitial calcifications were associated with progressive plaques. Arteries with intimal calcification had more severe luminal stenosis than those without (46% versus 21%; P<0.001). Conclusions- Our histological findings indicate that the presence of intracranial artery calcification has 3 patterns, including intimal, internal elastic lamina, and adventitial calcifications. But only intimal calcification is related with progressive atherosclerotic lesions, indicative of a proxy for intracranial atherosclerosis.

Intracranial calcifications on CT: an updated review

Intracranial calcifications are frequently encountered in non-contrast computed tomography scan in both adult and pediatric age groups. They refer to calcifications within the brain parenchyma or vasculature and can be classified into several major categories: physiologic/age-related, dystrophic, congenital disorders/phakomatoses, infectious, vascular, neoplastic, metabolic/endocrine, inflammatory and toxic diseases. In this updated review, we present a wide spectrum of intracranial calcifications from both pediatric and adult populations focusing on their pattern, size and location.

Vertebrobasilar artery calcification: Prevalence and risk factors in the general population

BACKGROUND AND AIMS

Arteriosclerosis in the vertebrobasilar arteries may play an important role in the etiology of posterior circulation strokes, but little is known on its prevalence, its correlation with arteriosclerosis in other major arteries, and its risk factors. Hence, we investigated these aspects of vertebrobasilar artery calcification (VBAC) as marker of vertebrobasilar arteriosclerosis.

METHODS

To quantify VBAC, 2483 participants (mean age: 69.2 years, 52% female) from the Rotterdam Study underwent non-enhanced computed tomography. We determined the presence and volume of VBAC. Next, using Spearman's rank correlation, we examined the correlation between the volume of VBAC and the volume of coronary artery calcification (CAC), aortic arch calcification (AAC), and both extracranial- (ECAC), and intracranial carotid artery calcification (ICAC). Finally, we investigated associations of cardiovascular risk factors with the presence and volume of VBAC using logistic and linear regression models.

RESULTS

The overall prevalence of VBAC was 21.0% (median volume: 7.3 mm³ [IQR: 2.0-25.6]). Correlations between VBAC and CAC, AAC, ECAC, and ICAC were weak to moderate (men: 0.33, 0.28, 0.30, 0.36; women: 0.26, 0.24, 0.24, 0.35, respectively). Hypertension, diabetes, and current smoking were associated with the presence of VBAC in both sexes (men: OR 1.67 [95%-CI, 1.14-2.46], 1.60 [95%-CI, 1.10-2.34], 1.48 [95%-CI, 1.02-2.14]; women: OR 1.51 [95%-CI, 1.01-2.26], 1.56 [95%-CI, 1.02-2.39], 1.53 [95%CI, 1.00-2.33], respectively). In men, obesity was also associated with VBAC (1.42 [95%-CI, 1.00-2.02]).

CONCLUSIONS

VBAC occurs in over 20% of elderly community dwelling persons. Cardiovascular risk factors are associated with VBAC with similar patterns for men and women.

Correlation Between Intracranial Arterial Calcification and Imaging of Cerebral Small Vessel Disease

Background and Purpose: Vascular calcification is part of the atherosclerotic process. Intracranial artery calcification is closely associated with cerebral small vessel disease (SVD). The present study aimed to investigate the distribution pattern of intracranial arterial calcification and its association with magnetic resonance imaging (MRI) markers of SVD in patients with acute ischemic cerebrovascular disease. Methods: Two hundred and seventy six consecutive patients with transient ischemic attack (TIA) or acute ischemic stroke who underwent both computed tomography (CT) angiography and MRI were enrolled in this study. Intracranial arterial calcium scores were evaluated using Agatston method. MRI was performed to assess cerebral infarction, white matter hyperintensities (WMHs), lacunes, cerebral microbleeds (CMBs), and enlarged perivascular spaces (EPVSs). Results: Intracranial artery calcification was present in 200 (72.46%) patients, with the highest prevalence in the internal carotid arteries (ICA) (64.8%). The severity of intracranial arterial calcification was associated with the presence of WMHs (P = 0.0001), lacunes (P = 0.0001), and CMBs (P = 0.0001); however, there was no association between calcifications and the presence of EPVSs (P = 0.058). The correlation coefficients (r_s) were 0.350, 0.142, 0.285, and 0.251 for WMHs, EPVSs, lacunes, and CMBs, respectively. The adjusted odds ratios (ORs) of intracranial arterial calcification were: 2.747 for WMH (grade 1-2), 3.422 for WMH (grade 3), 2.902 for lacunes, 2.449 for CMB, 0.88 for EPVS (grade 1), and 0.295 for EPVS (grade 2-4). Conclusion: Intracranial artery calcification is common in patients with ischemic cerebrovascular disease and the intracranial carotid artery is most frequently affected. Intracranial arterial calcifications might be associated with imaging markers of SVD and are highly correlated with WMHs, lacunes, and CMBs. Quantification of calcification on CT provides additional information on the pathophysiology of SVD. Intracranial arterial calcification could act as a potential marker of SVD.

Intracranial arterial wall imaging: Techniques, clinical applicability, and future perspectives

Purpose

To review the current state of the art and future development of intracranial vessel wall imaging.

Methods

Recent literature review and expert opinion about intracranial arterial wall imaging.

Results

Intracranial large artery diseases represent an important cause of stroke and vascular cognitive impairment worldwide. Our traditional understanding of intracranial large artery diseases is based on the observation of luminal narrowing or occlusion with angiographic or ultrasound techniques. Recently, novel imaging techniques have made the intracranial artery wall accessible for noninvasive visualization. The main advantage of vessel-wall imaging as compared to conventional imaging techniques for visualization of intracranial arteries is the ability to detect vessel wall changes even before they get to cause any significant luminal stenosis. This diagnostic capacity is provoking a revolutionary change in the way we see the intracranial circulation. In this article, we will review the current state of magnetic resonance imaging and computed tomography-based intracranial arterial wall imaging, focusing on technical considerations and their clinical applicability. Moreover, we will provide the readers with our vision on the future development of vessel-wall imaging techniques.

Conclusion

Intracranial arterial wall imaging methods are gaining increasing potential to impact the diagnosis and treatment of patients with cerebrovascular diseases.

Intracranial Arterial Calcification in Black Africans with Acute Ischaemic Stroke

Background

Intracranial arterial calcification (IAC), a recognized marker of atherosclerosis on cranial computed tomography (CT), is an independent risk factor for ischaemic stroke. This study aimed to determine the prevalence, distribution, severity, and associations of IAC in adults with acute ischaemic stroke (AIS) at the University College Hospital, Ibadan, Nigeria.

Methods

Cranial CT images of 130 consecutive adults who presented with AIS were acquired on a 64-slice multi-detector Toshiba Aquilion scanner and evaluated for IAC in bone window on Vitrea® software using a semi-quantitative scoring method for extent, thickness, and length of calcifications in the large intracranial arteries. Associations of IAC with clinical and laboratory data were determined by statistical analysis at p < 0.05.

Results

There were 71 males (54.6%), and the mean age of all patients was 63.0 ± 13.2 years. Hypertension was the most common risk factor (83.1%). IAC was found in 121 patients (93.1%), predominantly in the carotid siphon (86.1%) followed by the intracranial vertebral arteries (9.3%), middle cerebral arteries (2.4%), basilar artery (1.2%), and the anterior cerebral arteries (1%). The burden of IAC ranged from mild (17.4%) to moderate (52.1%) to severe (30.6%). Age (p < 0.001), diastolic blood pressure (p = 0.037), and alcohol use (0.046) were significantly different among the patients with mild, moderate, and severe degrees of IAC. IAC was associated with age (p < 0.001), hypertension (p = 0.03), diabetes mellitus (p = 0.02), hyperlipidaemia (p = 0.04), and alcohol use (p < 0.001) but not with sex (p = 0.35).

Conclusions

The burden of IAC is very high among native African patients with AIS and preferentially involves proximal inflow arteries. Therefore, the role of large vessel atherosclerosis in ischaemic stroke in native Africans should be explored in future multinational, multimodality studies.

Histological Characteristics of Intracranial Atherosclerosis in a Chinese Population: A Postmortem Study

Background

Anterior and posterior circulation atherosclerosis differ in vascular risk factors and stroke mechanisms. However, few studies have compared the pathological features between these lesions. Using a series of intracranial artery specimens, we characterized the intracranial atherosclerotic lesions and compared pathological features among different arteries of the intracranial vasculature.

Methods

Intracranial large arteries of 32 consecutively recruited autopsy cases of Chinese adults aged 45 years or older were examined pathologically using routine histology and immunostaining, to characterize the pathological features of the atherosclerotic lesions. We analyzed middle cerebral arteries (MCAs) (both left and right), vertebral arteries (VAs) (side more affected), and basilar arteries (BAs).

Results

Progressive atherosclerotic lesions were present in 91(71%) of the 128 arteries examined. Features of complicated plaques were infrequently detected: plaque hemorrhage was encountered in 12%, neovasculature in 12%, lumen thrombi in 13%, macrophage infiltration in 20%, and calcification in 25% of arteries. Luminal narrowing of MCA was the most severe, followed by VA; the BA least stenotic (37 ± 25 vs. 30 ± 24 vs. 20 ± 20%, all p < 0.05). MCA had more eccentric (vs. concentric) plaques than VA (69 vs. 25%, p = 0.003) and BA (69 vs. 38%; p = 0.03). Lumen thrombi were more frequent in BA, and calcification most commonly occurred in VA atherosclerotic lesions.

Conclusion

Intracranial atherosclerotic plaques were commonly present in this sample, but the lesions generally lacked features of complicated plaques. MCA lesions had demonstrable differences compared with VA and BA lesions. Further studies are needed to determine whether these characteristics indicate a distinctive atherosclerotic phenotype for the intracranial vasculature.

Intracranial Atherosclerosis: From Microscopy to High-Resolution Magnetic Resonance Imaging

Intracranial atherosclerosis is one of the leading causes of ischemic stroke and occurs more commonly in patients of Asian, African or Hispanic origin than in Caucasians. Although the histopathology of intracranial atherosclerotic disease resembles extracranial atherosclerosis, there are some notable differences in the onset and severity of atherosclerosis. Current understanding of intracranial atherosclerotic disease has been advanced by the high-resolution magnetic resonance imaging (HRMRI), a novel emerging imaging technique that can directly visualize the vessel wall pathology. However, the pathological validation of HRMRI signal characteristics remains a key step to depict the plaque components and vulnerability in intracranial atherosclerotic lesions. The purpose of this review is to describe the histological features of intracranial atherosclerosis and to state current evidences regarding the validation of MR vessel wall imaging with histopathology.

High Extent of Intracranial Carotid Artery Calcification Is Associated with Downstream Microemboli in Stroke Patients

BACKGROUND

Intracranial arterial calcification (ICAC) is frequently detected on head computed tomography and has been found to be associated with ischemic stroke by recent clinical studies.

AIMS

Based on a hospital-based study, we aimed to compare the occurrence of cerebral microembolic signals (MES) among stroke patients with different degrees of ICAC, which may indicate the potential mechanisms linking ICAC and ischemic stroke in intracranial atherosclerosis patients.

METHODS

This is a post-hoc analysis of our previous clinical study in 2005-2007, recruiting consecutive ischemic stroke patients with middle cerebral artery territory infarctions and good temporal window for MES monitoring. The degrees of ICAC in the Circle of Willis, especially calcification in the ipsilateral intracranial internal carotid artery (iICA), were evaluated both qualitatively and quantitatively on unenhanced head computed tomography.

RESULTS

Among the 68 recruited patients, MES was detected in 26 patients (38.24%). The overall degree of ICAC in the Circle of Willis was similar between patients with and without MES. For calcification in ipsilateral iICA, the presence of MES was more frequent in the high extent group (widest arc of calcification ≥90°) than in the low extent group (54.2% versus 29.5%, P = .046). Logistic regression found that a high extent ipsilateral iICA calcification was an independent risk factor of MES (odds ratio: 3.134; 95% confidence interval, 1.029-9.543; P = .044).

CONCLUSIONS

MES is frequently detected in patients with a high extent of ipsilateral iICA calcification, which suggests that a high extent of iICA calcification indicates artery vulnerability and accounts for the occurrence of microemboli in the corresponding artery.

Postmortem Study of Validation of Low Signal on Fat-Suppressed T1-Weighted Magnetic Resonance Imaging as Marker of Lipid Core in Middle Cerebral Artery Atherosclerosis

Background and Purpose—

High signal on T1-weighted fat-suppressed images in middle cerebral artery plaques on ex vivo magnetic resonance imaging was verified to be intraplaque hemorrhage histologically. However, the underlying plaque component of low signal on T1-weighted fat-suppressed images (LST1) has never been explored. Based on our experience, we hypothesized that LST1 might indicate the presence of lipid core within intracranial plaques.

Methods—

1.5 T magnetic resonance imaging was performed in the postmortem brains to scan the cross sections of bilateral middle cerebral arteries. Then middle cerebral artery specimens were removed for histology processing. LST1 presence was identified on magnetic resonance images, and lipid core areas were measured on the corresponding histology sections.

Results—

Total 76 middle cerebral artery locations were included for analysis. LST1 showed a high specificity (96.9%; 95% confidence interval, 82.0%–99.8%) but a low sensitivity (38.6%; 95% confidence interval, 24.7%–54.5%) for detecting lipid core of all areas. However, the sensitivity increased markedly (81.2%; 95% confidence interval, 53.7%–95.0%) when only lipid cores of area ≥0.80 mm² were included. Mean lipid core area was 5× larger in those with presence of LST1 than in those without (1.63±1.18 mm² versus 0.32±0.31 mm²; P=0.003).

Conclusions—

LST1 is a promising imaging biomarker of identifying intraplaque lipid core, which may be useful to distinguish intracranial atherosclerotic disease from other intracranial vasculopathies and to assess plaque vulnerability for risk stratification of patients with intracranial atherosclerotic disease. In vivo clinical studies are required to explore the correlation between LST1 and clinical outcomes of patients with intracranial atherosclerotic disease.

Intracranial Artery Calcification and Its Clinical Significance

Intracranial arterial calcification (IAC) is an easily identifiable entity on plain head computed tomography scans. Recent studies have found high prevalence rates for IAC worldwide, and this may be associated with ischemic stroke and cognitive decline. Aging, traditional cardiovascular risk factors, and chronic kidney disease have been found to be associated with IAC. The severity of IAC can be assessed using different visual grading scales or various quantitative methods (by measuring volume or intensity). An objective method for assessing IAC using consistent criteria is urgently required to facilitate comparisons between multiple studies involving diverse populations. There is accumulating evidence from clinical studies that IAC could be utilized as an indicator of intracranial atherosclerosis. However, the pathophysiology underlying the potential correlation between IAC and ischemic stroke-through direct arterial stenosis or plaque stability-remains to be determined. More well-designed clinical studies are needed to explore the predictive values of IAC in vascular events and the underlying pathophysiological mechanisms.

Middle Cerebral Artery Calcification: Association With Ischemic Stroke

Calcification of the middle cerebral artery (MCA) is uncommon in the healthy elderly. Whether calcification of the MCA is associated with cerebral ischemic stroke remains undetermined. We intended to investigate the association using Agatston calcium scoring of the MCA. This study retrospectively included 354 subjects with ischemic stroke in the MCA territory and 1518 control subjects who underwent computed tomography (CT) of the brain. We recorded major known risk factors for ischemic stroke, including age, gender, hypertension, diabetes mellitus, smoking, hyperlipidemia, and obesity, along with the MCA calcium burden, measured with the Agatston calcium scoring method. Univariate and modified logistic regression analyses were performed to examine the association between the MCA calcification and ischemic stroke. The univariate analyses showed significant associations of ischemic stroke with age, hypertension, diabetes mellitus, smoking, total MCA Agatston score, and the presence of calcification on both or either side of the MCA. Subjects with the presence of MCA calcification on both or either side of the MCA were 8.46 times (95% confidence interval, 4.93-14.53; P < 0.001) more likely to have a cerebral infarct than subjects without MCA calcification after adjustment for the major known risk factors, including age, hypertension, diabetes mellitus, and smoking. However, a higher degree of MCA calcification reflected by the Agatston score was not associated with higher risk of MCA ischemic stroke after adjustment for the confounding factors and presence of MCA calcification. These results suggest that MCA calcification is associated with ischemic stroke in the MCA territory. Further prospective studies are required to verify the clinical implications of the MCA calcification.

Cerebral arterial calcification is an imaging prognostic marker for revascularization treatment of acute middle cerebral arterial occlusion

BACKGROUND AND PURPOSE

To study the significance of intracranial artery calcification as a prognostic marker for acute ischemic stroke patients undergoing revascularization treatment after middle cerebral artery (MCA) trunk occlusion.

METHODS

Patients with acute MCA trunk occlusion, who underwent intravenous and/or intra-arterial revascularization treatment, were enrolled. Intracranial artery calcification scores were calculated by counting calcified intracranial arteries among major seven arteries on computed tomographic angiography. Patients were divided into high (HCB; score ≥3) or low calcification burden (LCB; score <3) groups. Demographic, imaging, and outcome data were compared, and whether HCB is a prognostic factor was evaluated. Grave prognosis was defined as modified Rankin Scale 5-6 for this study.

RESULTS

Of 80 enrolled patients, the HCB group comprised 15 patients, who were older, and more commonly had diabetes than patients in the LCB group. Initial National Institutes of Health Stroke Scale (NIHSS) scores did not differ (HCB 13.3±2.7 vs. LCB 14.6±3.8) between groups. The final good reperfusion after revascularization treatment (thrombolysis in cerebral infarction score 2b-3, HCB 66.7% vs. LCB 69.2%) was similarly achieved in both groups. However, the HCB group had significantly higher NIHSS scores at discharge (16.0±12.3 vs. 7.9±8.3), and more frequent grave outcome at 3 months (57.1% vs. 22.0%) than the LCB group. HCB was proven as an independent predictor for grave outcome at 3 months when several confounding factors were adjusted (odds ratio 4.135, 95% confidence interval, 1.045-16.359, P=0.043).

CONCLUSIONS

Intracranial HCB was associated with grave prognosis in patients who have undergone revascularization for acute MCA trunk occlusion.

Differences in plaque morphology and correlation of stenosis at the carotid artery bifurcation and the carotid siphon

OBJECTIVE

The purpose of this study was to compare the type of plaque and the degree of stenosis in the carotid artery bifurcation and the carotid siphon to explore potential correlations between these parameters.

MATERIALS AND METHODS

A total of 119 patients (87 men, 32 women; mean age, 69 years) were retrospectively studied using MDCT angiography. Component types of the carotid artery bifurcation and the carotid siphon plaque were defined according to attenuation values, and the volumes of each plaque component were calculated. The degree of stenosis was calculated according to the North American Symptomatic Endarterectomy Trial method. Data were compared using the Wilcoxon signed-rank test, Spearman correlation analysis, and receiver operating characteristic (ROC) analysis.

RESULTS

The results of the Wilcoxon test showed a statistically significant difference (p = 0.0001) between the degree of stenosis at the carotid artery bifurcation and that at the carotid siphon. We observed a statistically significant difference (p = 0.0001) between the total volumes of the carotid artery bifurcation (mean value, 748 mm(3)) and the carotid siphon (mean value, 54 mm(3)) plaque. Moreover, the respective mean percentages of calcified, mixed, and lipid components of plaque were 17%, 56%, and 27% in the carotid artery bifurcation and 73%, 19%, and 8% in the carotid siphon, showing a statistically significant difference (p = 0.001). ROC analysis did not show association between carotid siphon plaque volume and previous cerebrovascular events (Az = 0.562; p = 0.149), whereas the total volume of the carotid artery bifurcation plaque--and, in particular, the volume of the lipid components--showed a statistically significant association (Az = 0.691, and Az = 0.758; p < 0.001).

CONCLUSION

No significant association was found between presence of mixed and fatty components of plaque in the carotid artery bifurcation and presence of similar components in the carotid siphon. The carotid artery bifurcation total plaque volume (and, in particular, carotid artery bifurcation lipid volume) was associated with previous cerebrovascular events, whereas no association with the volume of carotid siphon plaque (and its subcomponents) was found.

Prevalence and long-term clinical significance of intracranial atherosclerosis after ischaemic stroke or transient ischaemic attack: a cohort study

OBJECTIVES

We investigated the prevalence and long-term risk associated with intracranial atherosclerosis identified during routine evaluation.

DESIGN

This study presents data from a prospective cohort of patients admitted to our stroke unit for thrombolysis evaluation.

SETTING AND PARTICIPANTS

We included 652 with a final diagnosis of ischaemic stroke or transient ischaemic attack (TIA) from April 2009 to December 2011. All patients were acutely evaluated with cerebral CT and CT angiography (CTA). Acute radiological examinations were screened for intracranial arterial stenosis (IAS) or intracranial arterial calcifications (IAC). Intracranial stenosis was grouped into 30-50%, 50-70% and >70% lumen reduction. The extent of IAC was graded as number of vessels affected.

PRIMARY AND SECONDARY OUTCOME MEASURE

Patients were followed until July 2013. Recurrence of an ischaemic event (stroke, ischaemic heart disease (IHD) and TIA) was documented through the national chart system. Poor outcome was defined as death or recurrence of ischaemic event.

RESULTS

101 (15.5%) patients showed IAS (70: 30-50%, 29: 50-70% and 16: >70%). Two-hundred and fifteen (33%) patients had no IAC, 339 (52%) in 1-2 vessels and 102 (16%) in >2 vessels. During follow-up, 53 strokes, 20 TIA and 14 IHD occurred, and 95 patients died. The risk of poor outcome was significantly different among different extents of IAS as well as IAC (log-rank test p<0.01 for both). In unadjusted analysis IAS and IAC predicted poor outcome and recurrent ischaemic event. When adjusted, IAS and IAC independently increased the risk of a recurrent ischaemic event (IAS: HR 1.67; CI 1.04 to 2.64 and IAC: HR 1.22; CI 1.02 to 1.47).

CONCLUSIONS

Intracranial atherosclerosis detected during acute evaluation predicts an increased risk of recurrent stroke.

Role of noncontrast head CT in the assessment of vascular abnormalities in the emergency room

Noncontrast CT of the head is a widely used noninvasive investigation for a variety of acute and chronic neurological conditions. Since CT head without contrast is usually the first and often the only investigation in the emergency room for many neurological symptoms, it is imperative to detect subtle vascular changes, which in many patients can be life-saving. The vascular abnormalities may present with increased density and/or size of the vessels, filling defects, and be associated with parenchymal and bony changes. In this article, we present examples of several vascular pathologies which can be identified on the noncontrast CT of the head, and learn imaging and interpretation techniques to help recognize what often are nebulous changes. While some of the findings are diagnostic by themselves and others subtle, any suspicious abnormality should be followed with dedicated vascular imaging such as CT/MR angiogram, venogram, or catheter angiogram for confirmation and better characterization.

Noninvasive assessment of the carotid and cerebrovascular atherosclerotic plaques by multidetector CT in type-2 diabetes mellitus patients with transient ischemic attack or stroke

BACKGROUND

The cerebrovasuclar artery disease as a common complication of type-2 diabetes mellitus (T2DM) caused huge economic burden and lives threatening to patients. We evaluated the prevalence and morphology of carotid and cerebrovascular atherosclerotic plaques in T2DM patients with transient ischemic attack (TIA) or stroke using multidetector CT (MDCT).

METHODS

64-MDCT and dual-source CT (DSCT) angiographies were performed in 195 T2DM patients with TIA or stroke (mean age 65.7+/-12.8 years; 118 men) between January 2009 to August 2011. During the process, plaque type, its distribution, extensive and obstructive natures were determined for each segment derived from the patients.

RESULTS

Atherosclerotic plaques were detected in 183 (93.8%) patients. A total of 1056 segments with plaque were identified, of which 450 (42.6%) were non-calcified, 192 (18.2%) were mixed and 414 (39.2%) calcified ones. Among them, 562 (53.2%) resulted in mild stenosis, 291 (27.6%) moderate stenosis, 170 (16.1%) severe stenosis and 33 (3.1%) occlusion. Non-calcified plaques contributed 91.8% to non-obstructive lumen narrowing, while mixed and calcified plaques contributed 89.0% and 65.0% respectively.

CONCLUSIONS

MDCT angiography detected a high prevalence of plaques in T2DM patients with TIA or stroke. A relatively high proportion of plaques were non-calcified, as well as with non-obstructive stenosis. MDCT angiography might further enhance the detection and management of carotid and cerebrovascular atherosclerosis in T2DM patients with TIA and stroke.