Intracranial Artery Calcification Research Articles

Intracranial and heart valve calcifications in hemodialysis patients-Interrelationship and clinical impact.

Arterial calcification is an integral component of active atherosclerosis and is an independent risk factor for cardiovascular disease. Atherosclerosis is a systemic, life-threating disease that may occur at different sites and in various clinical presentations. Intracranial and valvular calcifications are common among dialysis patients and have been associated with poor cardiovascular outcomes. The aim of this study was to assess the clinical impact of valvular and intracranial arterial calcifications on mortality among chronic hemodialysis patients. A blinded neuroradiologist graded intracranial calcifications (ICC) of all hemodialysis patients who underwent brain computerized tomography (CT) from 2015 to 2017 in our institution. Valvular calcifications were assessed by echocardiography. Only hemodialysis patients with available echocardiography and brain CT were included. This study included 119 patients (mean age 70.6 ± 12.6 years, 57.1% men, and mean dialysis vintage 25.8 ± 42.6months). Among the cohort, 19 (16%) had no cardiac or brain calcifications and 65 (54.6%) had both valvular and intracranial calcifications. Considering the patients with no calcification as the reference group yielded adjusted odds ratios for all-cause mortality of 3.68 (95%CI 1.55-8.75) among patients with any brain calcifications, p=0.002. While valvular calcifications alone did not increase the 1-year mortality rate, ICC was the most important predictor of all-cause 1-year mortality in the study cohort. We found an independent association between ICC and the risk of death among hemodialysis patients. Assessing ICC may contribute to the risk stratification of hemodialysis patients. These calcifications are no less important than valvular calcifications.

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

ObjectiveTo investigate the correlation between prognosis and intracranial carotid artery calcification (ICAC) in patients with acute ischemic stroke (AIS) who receive intravenous thrombolysis (IVT).MethodsA 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.ResultsCompared 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.ConclusionICAC is closely related to the prognosis of acute ischemic stroke after intravenous thrombolysis.

Internal carotid artery calcifications in a South African population: A CBCT imaging study

AbstractBackgroundStroke is the second leading cause of death globally and account for 25,000 deaths annually in South Africa. Both medial and intimal located intracranial internal carotid artery (iICA) calcifications are associated with stroke. Cone beam computed tomography (CBCT) is commonly used where advanced dental imaging of the skull is required and often includes areas outside of the field of interest. Modalities such as CBCT have great potential to identify and provide early detection of calcifications during imaging for dental purposes. The aim of the study was to investigate the presence, distribution and extent of iICA calcifications in a South African population using CBCT images. Retrospectively collected CBCT data sets of 582 patients were evaluated. All data sets were evaluated for the presence, location and severity of calcifications within the course of the internal carotid artery.ResultsAge was associated with a higher prevalence of internal carotid artery (ICA) calcifications, but sex was not. Individuals older than 61 years presented with a high number of calcifications. In total, the presence of calcifications was found in 199 patients (i.e. 34.19% of the patients). White South African individuals showed the highest prevalence. A higher degree of calcifications was also present within the C4, C5 and C6 ICA segments.ConclusionsDetection of calcifications along the course of the ICA was possible using CBCT images taken for dental treatment purposes. Early detection of calcifications allows for appropriated referral and assessment which will be beneficial to the patient presenting with ICA calcifications.

Prevalence of dementia and mild cognitive impairment in indigenous Bolivian forager-horticulturalists.

We evaluated the prevalence of dementia and mild cognitive impairment (MCI) in indigenous Tsimane and Moseten, who lead a subsistence lifestyle. Participants from population-based samples ≥60 years of age (n=623) were assessed using adapted versions of the Modified Mini-Mental State Examination, informant interview, longitudinal cognitive testing and brain computed tomography (CT) scans. Tsimane exhibited five cases of dementia (among n=435; crude prevalence=1.2%, 95% confidence interval [CI]: 0.4, 2.7); Moseten exhibited one case (among n=169; crude prevalence=0.6%, 95% CI: 0.0, 3.2), all age≥80 years. Age-standardized MCI prevalence was 7.7% (95% CI: 5.2, 10.3) in Tsimane and 9.8% (95% CI: 4.9, 14.6) in Moseten. Cognitive impairment was associated with visuospatial impairments, parkinsonian symptoms, and vascular calcification in the basal ganglia. The prevalence of dementia in this cohort is among the lowest in the world. Widespread intracranial medial arterial calcifications suggest a previously unrecognized, non-Alzheimer's disease (AD) dementia phenotype.

Intracranial internal carotid artery calcification is not predictive of future cognitive decline

BackgroundIntracranial internal carotid artery (ICA) calcification is a common incidental finding in non-contrast head CT. We evaluated the predictive value of ICAC (ICAC) for future risk of cognitive decline and compared the results with conventional imaging biomarkers of dementia.MethodsIn a retrospective observational cohort, we included 230 participants with a PET-CT scan within 18 months of a baseline clinical assessment and longitudinal imaging assessments. Intracranial ICAC was quantified on baseline CT scans using the Agatson calcium score, and the association between baseline ICA calcium scores and the risk of conversion from a CDR of zero in baseline to a persistent CDR > 0 at any follow-up visit, as well as longitudinal changes in cognitive scores, were evaluated through linear and mixed regression models. We also evaluated the association of conventional imaging biomarkers of dementia with longitudinal changes in cognitive scores and a potential indirect effect of ICAC on cognition through these biomarkers.ResultsBaseline ICA calcium score could not distinguish participants who converted to CDR > 0. ICA calcium score was also unable to predict longitudinal changes in cognitive scores, imaging biomarkers of small vessel disease such as white matter hyperintensities (WMH) volume, or AD such as hippocampal volume, AD cortical signature thickness, and amyloid burden. Severity of intracranial ICAC increased with age and in men. Higher WMH volume and amyloid burden as well as lower hippocampal volume and AD cortical signature thickness at baseline predicted lower Mini-Mental State Exam scores at longitudinal follow-up. Baseline ICAC was indirectly associated with longitudinal cognitive decline, fully mediated through WMH volume.ConclusionsIn elderly and preclinical AD populations, atherosclerosis of large intracranial vessels as demonstrated through ICAC is not directly associated with a future risk of cognitive impairment, or progression of imaging biomarkers of AD or small vessel disease.

Intracranial Arterial Calcification and Intracranial Atherosclerosis: Close but Different.

Background and PurposeIntracranial 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.MethodsConsecutive 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.ResultsAmong 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).ConclusionOur 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.

Abstract TP108: Intracranial Artery Calcification: Frequency, Determinants, And Modification Of Outcomes From Endovascular Thrombectomy

Introduction: Intracranial artery calcification (ICAC) is a common finding on CTA in patients presenting with LVO acute ischemic stroke and could potentially serve as a useful biomarker of intracranial atherosclerosis and altered intracranial vessel pliability in patients undergoing endovascular thrombectomy (EVT). However, ICAC frequency, determinants, and outcome associations have not been well delineated. Methods: In a prospectively maintained database, we analyzed consecutive patients undergoing CTA immediately prior to EVT from Mar 2016 - Aug 2020. Extent of ICAC in the intracranial ICA or VA proximal to the target vessel was scored using a validated grading scale (Babiarz et al, AJNR 2003: 5 levels for greatest calcific thickness and 5 levels for greatest circumferential extent). Example cases in Figure 1. Patients were stratified into low (0-2), medium (3-4), and high (5-6) ICAC groups. Results: Among 91 patients, mean age was 73, 54% female, and mean NIHSS 17. Median ICAC score was 3 [IQR 0-4]. Baseline characteristics associated with higher ICAC scores were: CAD (3.8 vs. 2.4, p = 0.02), HTN (3.1 vs. 2.1, p = 0.07), and age ( r = 0.50, p &lt; 0.001). There was a U-shaped association between ICAC score and successful reperfusion (mTICI 2b-3): 90.9%, 65.7%, and 95.0% in low, medium, and high ICAC score groups, respectively ( p = 0.006). Need for rescue intervention (angioplasty/stenting, IA thrombolysis, or GpIIb/IIIa inhibitor) was higher in the high ICAC group: 5.9% vs. 5.6% vs. 28.6% ( p = 0.01). Functional independence (mRS 0-2) at discharge (29.4% vs. 22.2% vs. 19.0%, p = 0.64) or 90 days (40.0% vs. 30.0% vs. 21.4%, p = 0.22) did not differ, nor did symptomatic intracranial hemorrhage ( p = 0.96). Conclusions: Calcification of intracranial vessels is frequently seen on CTA in LVO patients and is associated with age and vascular risk factors. Degree of calcification has important associations with rates of successful reperfusion and need for rescue intervention during EVT.

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?

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. 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. 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. 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.

Helicobacter pylori Infection Acts as an Independent Risk Factor for Intracranial Atherosclerosis in Women Less Than 60 Years Old.

Background: Studies show inconsistent results regarding the relationship between Helicobacter pylori (H. pylori) infection and stroke. The present study assessed a potential association between H. pylori infection and an important risk factor for stroke, intracranial atherosclerosis.Methods: In total, 15,798 subjects with transcranial Doppler (TCD) and 13C-urea breath test (13C-UBT) were enrolled from March 2012 to March 2017. Intracranial atherosclerosis was further measured using intracranial carotid artery calcification (ICAC) on past or recent head CT, and 14,084 subjects were ultimately included in the study. Baseline demographics, atherosclerosis risk factors, and laboratory results were investigated. Since endothelial dysfunction is critical to the development of atherosclerosis, the role of H. pylori in migration, tube formation, and proliferation of human brain microvascular endothelial cells (HBMECs) was assessed in vitro.Results: The intracranial atherosclerosis group had a higher proportion of women and a greater rate of H. pylori infection than those without intracranial atherosclerosis. H. pylori infection was significantly more common in women with intracranial atherosclerosis than males. In addition, the incidence of intracranial atherosclerosis was significantly higher in women with H. pylori infection than uninfected women (53.8 vs. 46.4%, p < 0.001). In an adjusted model, H. pylori was shown to be an independent risk factor for intracranial atherosclerosis in women ≤ 60 years of age [odds ratio (OR) = 2.261, 95% CI = 1.839–2.780, p < 0.001]. Serum exosomes from patients with H. pylori infection had significantly reduced brain endothelial cell migration, tube formation, and proliferation in vitro.Conclusion: Helicobacter pylori infection may be an important independent risk factor for intracranial atherosclerosis in women ≤ 60 years of age.

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

BackgroundSilent 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. MethodsWe 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. ResultsTotally, 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). ConclusionsPatients 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.

Arterial calcification at different sites and prediction of atherosclerotic cardiovascular disease among women and men

Background and aimsThe sex-specific contributions of arterial calcification to atherosclerotic cardiovascular disease (ASCVD) risk prediction and stratification in the light of recent modifications by cardiovascular prevention guidelines remain unclear. We assessed the sex-specific value of calcification in different arteries, beyond the Pooled Cohort Equations (PCE) risk factors, for 10-year ASCVD risk prediction. MethodsFrom 2003 to 2006, participants from the population-based Rotterdam Study (n = 2167) underwent CT to quantify coronary artery calcification (CAC), aortic arch calcification (AAC), extracranial (ECAC) and intracranial carotid artery calcification (ICAC). Follow-up for ASCVD was complete on January 1, 2015. We refitted the PCE (base model), and categorized participants into low (<5%), borderline (5%–7.5%), intermediate (7.5%–20%), and high (≥20%) ASCVD risk. We extended the models with calcifications and calculated c-statistics and net reclassification improvements for events (NRIe) and non-events (NRIne). ResultsCAC predicted ASCVD in women [hazard-ratio (95%-CI) per 1-SD: 1.40 (1.14–1.73)] and men [1.62 (1.27–1.93)]. After addition of CAC to the base model, the c-statistic improved from 0.71 to 0.72 in women; from 0.65 to 0.68 in men. Addition of CAC led to NRIe of 14.3% in women, 4.8% in men and NRIne of 1.5% in women, 15.1% in men. Only in women, ICAC predicted ASCVD [hazard-ratio (95%-CI) per 1-SD: 1.62 (1.26–2.08)], and improved the model (c-statistic from 0.71 to 0.73, NRIe: 9.8% and NRIne: 5.9%). ConclusionsAssessment of CAC improves ASCVD risk prediction and stratification. In women, the added value of ICAC for ASCVD risk prediction is comparable to that of CAC.

Intracranial carotid artery calcification subtype and collaterals in patients undergoing endovascular thrombectomy

Background and aimsDistinct subtypes of intracranial carotid artery calcification (ICAC) have been found (i.e., medial and intimal), which may differentially be associated with the formation of collaterals. We investigated the association of ICAC subtype with collateral status in patients undergoing endovascular thrombectomy (EVT) for ischemic stroke. We further investigated whether ICAC subtype modified the association between collateral status and functional outcome. MethodsWe used data from 2701 patients with ischemic stroke undergoing EVT. Presence and subtype of ICAC were assessed on baseline non-contrast CT. Collateral status was assessed on baseline CT angiography using a visual scale from 0 (absent) to 3 (good). We investigated the association of ICAC subtype with collateral status using ordinal and binary logistic regression. Next, we assessed whether ICAC subtype modified the association between collateral status and functional outcome (modified Rankin Scale, 0–6). ResultsCompared to patients without ICAC, we found no association of intimal or medial ICAC with collateral status (ordinal variable). When collateral grades were dichotomized (3 versus 0–2), we found that intimal ICAC was significantly associated with good collaterals in comparison to patients without ICAC (aOR, 1.41 [95%CI:1.06–1.89]) or with medial ICAC (aOR, 1.50 [95%CI:1.14–1.97]). The association between higher collateral grade and better functional outcome was significantly modified by ICAC subtype (p for interaction = 0.01). ConclusionsPatients with intimal ICAC are more likely to have good collaterals and benefit more from an extensive collateral circulation in terms of functional outcome after EVT.

Intracranial vertebrobasilar arterial calcification as a predictor for ischemic stroke due to atherosclerotic disease

Intracranial vertebrobasilar arterial calcification as a predictor for ischemic stroke due to atherosclerotic disease

The Combined Prognostic Significance of Alkaline Phosphatase and Intracranial Arterial Calcifications in Hemodialysis Patients

Introduction: The prevalence of intracranial arterial calcification (ICAC) in maintenance hemodialysis (MHD) patients is about 90%, and its severity is correlated with age, hemodialysis vintage, and mineral bone disease. Elevated concentrations of calcium and phosphorus are not sufficient for medial calcification because of inhibition by pyrophosphate. Alkaline phosphatase (ALP) promotes calcification by hydrolyzing extracellular pyrophosphate. Epigenetic mechanisms involving ALP inhibition by apabetalone were investigated as a potential target for preventing vascular calcifications (VCs). This study assessed the combined impact of VCs and elevated serum ALP on mortality among chronic HD patients. Methods: VCs represented by ICAC were measured simultaneously with mineral bone disease parameters including serum ALP of MHD patients who underwent noncontrast brain computed tomography from 2015 to 2018 in our institution. Results: This retrospective study included 150 MHD patients (mean age 71.3 ± 12.1 years, 60.1% male). Of the total cohort, 12 (7.8%) had no brain calcifications and 69 (45.1%) had multiple intracranial calcifications. Considering the patients with normal ALP and no calcification as the reference group yielded adjusted odds ratios for all-cause mortality of 4.6 (95% CI: 1.7–12.7) among patients with brain calcifications and normal ALP (p = 0.003) and odds ratios for all-cause mortality of 6.1 (95% CI: 2.1–17.7) among patients with brain calcifications and elevated ALP (p= 0.001). Conclusion: We found an independent association between ICAC and the risk of death among MHD patients. The combined effect of ICAC and elevated ALP was associated with a higher odds ratio for all-cause mortality in MHD patients and may contribute to the risk stratification of these patients.

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.

Automated Segmentation and Volume Measurement of Intracranial Internal Carotid Artery Calcification at Noncontrast CT.

To develop and evaluate a fully-automated deep learning-based method for assessment of intracranial internal carotid artery calcification (ICAC). This was a secondary analysis of prospectively collected data from the Rotterdam study (2003-2006) to develop and validate a deep learning-based method for automated ICAC delineation and volume measurement. Two observers manually delineated ICAC on noncontrast CT scans of 2319 participants (mean age, 69 years ± 7 [standard deviation]; 1154 women [53.2%]), and a deep learning model was trained to segment ICAC and quantify its volume. Model performance was assessed by comparing manual and automated segmentations and volume measurements to those produced by an independent observer (available on 47 scans), comparing the segmentation accuracy in a blinded qualitative visual comparison by an expert observer, and comparing the association with first stroke incidence from the scan date until 2016. All method performance metrics were computed using 10-fold cross-validation. The automated delineation of ICAC reached a sensitivity of 83.8% and positive predictive value (PPV) of 88%. The intraclass correlation between automatic and manual ICAC volume measures was 0.98 (95% CI: 0.97, 0.98; computed in the entire dataset). Measured between the assessments of independent observers, sensitivity was 73.9%, PPV was 89.5%, and intraclass correlation coefficient was 0.91 (95% CI: 0.84, 0.95; computed in the 47-scan subset). In the blinded visual comparisons of 294 regions, automated delineations were judged as more accurate than manual delineations in 131 regions, less accurate in 94 regions, and equally accurate in the rest of the regions (131 of 225, 58.2%; P = .01). The association of ICAC volume with incident stroke was similarly strong for both automated (hazard ratio, 1.38 [95% CI: 1.12, 1.75]) and manually measured volumes (hazard ratio, 1.48 [95% CI: 1.20, 1.87]). The developed model was capable of automated segmentation and volume quantification of ICAC with accuracy comparable to human experts.Keywords CT, Neural Networks, Carotid Arteries, Calcifications/Calculi, Arteriosclerosis, Segmentation, Vision Application Domain, Stroke Supplemental material is available for this article. © RSNA, 2021.

Intracranial arteriosclerosis is related to cerebral small vessel disease: a prospective cohort study

Intracranial arteriosclerosis has been increasingly recognized as a risk factor for cognitive impairment and even dementia. A possible mechanism linking intracranial arteriosclerosis to cognitive impairment and dementia involves structural brain changes including cerebral small vessel disease (CSVD). To assess whether intracranial carotid artery calcification (ICAC) and vertebrobasilar artery calcification (VBAC), as proxies for intracranial arteriosclerosis, are related to CSVD.Within the population-based Rotterdam Study, between 2003 and 2006 a computed tomography (CT)-based measurement of ICAC and VBAC and at least one magnetic resonance imaging (MRI) measurement of structural brain changes were performed from 2005 onwards in 1,489 participants. To estimate the burden of calcification independent of age, we computed age-adjusted percentile curves for ICAC and VBAC separately, based on the calcification volumes. Using the longitudinal MRI data, we assessed whether a larger calcification burden accelerates structural brain changes using appropriate statistical models for repeated outcome measures. A larger burden of ICAC and VBAC was associated with an increase of CSVD markers accelerating over time. A larger burden of ICAC and VBAC was not significantly (p > 0.05) associated with accelerated brain atrophy. Arteriosclerosis is related to accelerating structural brain changes over time.

Computed tomography angiography findings predictive of post-intervention vasospasm in patients with aneurysmal subarachnoid hemorrhage.

To evaluate the association of CT/CT angiography (CTA) findings and clinical characteristics with subsequent vasospasm in patients with aneurysmal subarachnoid hemorrhage (aSAH). Consecutive presentation CTA head exams in patients with aSAH between January 2005 and June 2015 were retrospectively evaluated for intracranial arterial calcification, undulation and non-calcified stenosis. Additional variables including modified Fisher Scale (mFS), Glasgow Coma Scale (GCS) and neurological exam status were reviewed. Associations of CTA findings with the incidence of angiographic vasospasm were assessed with multivariate logistic regression models using the least absolute shrinkage and selection operator machine-learning algorithm. Model performance was summarized using c-index with bootstrap optimism-adjustment. Intracranial arterial calcification, seen in 51.7% of 195 total patients, was protective against vasospasm (OR-0.6; 95% CI-0.52-0.67; p = 0.009), while arterial undulation (24%) was associated with subsequent vasospasm (OR-2.6; 95% CI-1.3-5.1; p = 0.007). Non-calcified intracranial arterial stenosis (5%) was associated with subsequent vasospasm, (OR-4.7; 95% CI-1.0-22.8; p = 0.054). Least absolute shrinkage and selection operator selected all three CTA findings as predictors in a multivariate model for vasospasm in addition to clinical factors, which demonstrated superior predictive performance (c-index-0.74; 95% CI-0.69-0.82) compared to a model based on mFS and clinical factors only (c-index-0.66; 95% CI-0.57-0.75; p = 0.010 for the difference). Presentation CTA findings combined with clinical factors may better predict the development of vasospasm in patients with aSAH compared to current prognostic models alone. The combination of initial CT/CTA and clinical findings better predict development of vasospasm after aSAH. This can lead to better markers for use in future clinical trials to develop vasospasm preventative treatments and potentially provide better targets for early aggressive treatment.

Abstract P653: Intracranial Artery Calcification Variations by Stroke Subtypes

Introduction: Intracranial artery calcification (IAC) is a common radiological finding on Computed Tomography (CT) scan. Although IAC occurs with aging, it is uncertain whether IAC varies by stroke subtypes. Method: We included patients admitted to our hospital with acute stroke. We quantified calcification volume of both clinoid and siphon carotid arteries, vertebral arteries at the V4 segment, and the basilar artery using an in-house quantification tool for non-contrast brain CT. Stroke etiological subtypes were determined according to the Trial of Organon in Acute Stroke Trial (TOAST) classification system independent of the calcification quantification. Demographic and clinical information was extracted from the medical records. We determined the prevalence of IAC in 51% of patients. (31% anterior, 7% posterior, and 14 % in both circulations) Result: We included 694 patients with stroke history (mean age 68 ± 16, range 21-101, 55% women, 71% nonwhite or mixed). IAC was associated with male sex (OR 1.47 [95%-CI 1.41-2.08), older age (OR 1.05 [95%-CI, 1.04-1.06]), hypertension (OR 1.55 [95%-CI, 1.01-2.36], dyslipidemia (OR 1.54 [95%-CI, 1.06-2.25]), and smoking (OR 1.79 [95%-CI, 1.18-2.71]). Anterior IAC was associated with dyslipidemia (OR 1.57 [95%-CI, 1.08-2.28], smoking (1.9 [95%-CI, 1.25-2.88]), and older age (OR 1.05 [95%-CI, 1.36-1.66). Posterior IAC was associated with myocardial infarction (OR 1.58 [95%-CI, 1.01-2.47] and older age (OR 1.02 [95%-CI, 1.01-1.03]. In multivariate analyses, any IAC was associated with small artery disease stroke (OR 1.01[95%-CI, 1.41-3.98]). Stratifying by circulations, however, demonstrated that the association was only with posterior (OR 1.22[95%-CI, 1.02-2.28]) and not anterior IAC (OR 1.20[95%-CI, 0.86-1.1.69]). There was no association between IAC and intracranial large artery stenoses OR (1.22[95%-CI, 0.78-1.1.92]). Conclusion: IAC is a marker of arterial disease, and its prevalence relates to vascular risk factors and small artery disease strokes. Understanding the mechanism by which IAC may relate to small artery disease may help us understand small artery stroke physiopathology and discover novel therapies for its treatment.