Clinical Implication of Cerebral Artery Calcification on Brain CT

Burden of intracranial artery calcification in white patients with ischemic stroke

INTRODUCTION

The diagnostic workup of stroke doesn't identify an underlying cause in two-fifths of ischemic strokes. Intracranial arteriosclerosis is acknowledged as a cause of stroke in Asian and Black populations, but is underappreciated as such in whites. We explored the burden of Intracranial Artery Calcification (IAC), a marker of intracranial arteriosclerosis, as a potential cause of stroke among white patients with recent ischemic stroke or TIA.

PATIENTS AND METHODS

Between December 2005 and October 2010, 943 patients (mean age 63.8 (SD ± 14.0) years, 47.9% female) were recruited, of whom 561 had ischemic stroke and 382 a TIA. CT-angiography was conducted according to stroke analysis protocols. The burden of IAC was quantified on these images, whereafter we assessed the presence of IAC per TOAST etiology underlying the stroke and assessed associations between IAC burden, symptom severity, and short-term functional outcome.

RESULTS

IAC was present in 62.4% of patients. Furthermore, IAC was seen in 84.8% of atherosclerotic strokes, and also in the majority of strokes with an undetermined etiology (58.5%). Additionally, patients with larger IAC burden presented with heavier symptoms (adjusted OR 1.56 (95% CI [1.06-2.29]), but there was no difference in short-term functional outcome (1.14 [0.80-1.61]).

CONCLUSION

IAC is seen in the majority of white ischemic stroke patients, aligning with findings from patient studies in other ethnicities. Furthermore, over half of patients with a stroke of undetermined etiology presented with IAC. Assessing IAC burden may help identify the cause in ischemic stroke of undetermined etiology, and could offer important prognostic information.

Lower limb arterial calcification and its clinical relevance with peripheral arterial disease

Lower limb arterial calcification (LLAC) is associated with an increased risk of mortality and it predicts poor outcomes after endovascular interventions in patients with peripheral artery disease (PAD). Detailed histological analysis of human lower artery specimens pinpointed the presence of LLAC in two distinct layers: the intima and the media. Intimal calcification has been assumed to be an atherosclerotic pathology and it is associated with smoking and obesity. It becomes instrumental in lumen stenosis, thereby playing a crucial role in disease progression. On the contrary, medial calcification is a separate process, systematically regulated and linked with age advancement, diabetes, and chronic kidney disease. It prominently interacts with vasodilation and arterial stiffness. Given that both types of calcifications frequently co-exist in PAD patients, it is vital to understand their respective mechanisms within the context of PAD. Calcification can be easily identifiable entity on imaging scans. Considering the highly improved abilities of novel imaging technologies in differentiating intimal and medial calcification within the lower limb arteries, this review aimed to describe the distinct histological and imaging features of the two types of LLAC. Additionally, it aims to provide in-depth insight into the risk factors, the effects on hemodynamics, and the clinical implications of LLAC, either occurring in the intimal or medial layers.

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.

Calcified cerebral embolism: a 9 case series and review of the literature

OBJECTIVE

Calcified cerebral embolism (CCE), a rarely reported and underdiagnosed cause of stroke, may be the first manifestation of a vascular or cardiac disease. Our purpose is to describe the characteristics of CCE in a series of 9 cases and review the literature on the subject.

PATIENTS AND METHODS

We included patients with CCE from 3 different hospitals. We described the diagnostic approach, neuroimaging findings, origin of the embolism, treatment, and prognosis of these patients.

RESULTS

We identified a total of 9 patients presenting spontaneous CCE as the cause of acute ischaemic stroke. In all cases, the middle cerebral artery was affected; all patients underwent CT. A possible calcific source was found in 6 patients (66.6%), originated in the carotid arteries in 3 (33.3%) and in the heart in the other 3 patients (33.3%). Only one patient was treated in the acute phase (trombectomy) and only 11% of patients had modified ranking scale scores ≤ 2 at 3 months.

CONCLUSIONS

CCE is more frequent than previously thought and, although the condition continues to be underdiagnosed, it is of considerable prognostic relevance in the aetiological study of stroke.

Neuroimaging in the Era of Artificial Intelligence: Current Applications

BACKGROUND

Artificial intelligence (AI) in medicine has shown significant promise, particularly in neuroimaging. AI increases efficiency and reduces errors, making it a valuable resource for physicians. With the increasing amount of data processing and image interpretation required, the ability to use AI to augment and aid the radiologist could improve the quality of patient care.

OBSERVATIONS

AI can predict patient wait times, which may allow more efficient patient scheduling. Additionally, AI can save time for repeat magnetic resonance neuroimaging and reduce the time spent during imaging. AI has the ability to read computed tomography, magnetic resonance imaging, and positron emission tomography with reduced or without contrast without significant loss in sensitivity for detecting lesions. Neuroimaging does raise important ethical considerations and is subject to bias. It is vital that users understand the practical and ethical considerations of the technology.

CONCLUSIONS

The demonstrated applications of AI in neuroimaging are numerous and varied, and it is reasonable to assume that its implementation will increase as the technology matures. AI's use for detecting neurologic conditions holds promise in combatting ever increasing imaging volumes and providing timely diagnoses.

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.

Calcified cerebral embolism: a 9-case series and review of the literature

OBJECTIVE

Calcified cerebral embolus (CCE), a rarely reported and underdiagnosed cause of stroke, may be the first manifestation of a vascular or cardiac disease. We describe the characteristics of CCE in a series of 9 cases and review the literature on the subject.

PATIENTS AND METHODS

We included patients with CCE from 3 different hospitals. We describe the diagnostic approach, neuroimaging findings, origin of the embolism, treatment, and prognosis of these patients.

RESULTS

We identified a total of 9 patients presenting spontaneous CCE as the cause of acute ischaemic stroke. In all cases, the middle cerebral artery was affected; all patients underwent CT. A possible calcific source was found in 6 patients (66.6%), originating in the carotid arteries in 3 (33.3%) and in the heart in the other 3 patients (33.3%). Only one patient was treated in the acute phase (trombectomy) and only 11% of patients had modified Ranking Scale scores ≤ 2 at 3 months.

CONCLUSIONS

CCE is more frequent than previously thought and, although the condition continues to be underdiagnosed, it is of considerable prognostic relevance in the aetiological study of stroke.

Intracranial Vertebrobasilar Calcification in Patients with Ischemic Stroke is a Predictor of Recurrent Stroke, Vascular Disease, and Death: A Case-Control Study

Intracranial artery calcification can be detected on nonenhanced brain computer tomography (NECT) and is a predictor of early vascular events. Here, we assessed the impact of vertebrobasilar artery calcification (VBC) on the long-term risk for recurrent stroke and vascular events. We performed a case-control trial of all consecutive stroke patients admitted to the University Hospital of Maribor, Slovenia over a period of 14 months. VBC was defined as presence of a hyperdense area within vertebrobasilar arteries that exceeds > 90 Hounsfield units as seen on NECT. Clinical follow-up information was obtained from the hospital documentation system and mortality registry of the district and included recurrent stroke, subsequent vascular events (myocardial infarction, heart failure, peripheral arterial occlusive disease), and death. We followed a total of 448 patients for a median of 1505 days (interquartile range, IQR 188-2479). Evidence for VBC was present in 243 (54.2%) patients. Median age was 76 years, recurrent stroke occurred in 33 (7.4%), any vascular events in 71 (15.8%), and death in 276 (61.6%). VBC was associated with a higher risk of recurrent stroke (hazard ratio, HR 3.13, 95% confidence interval (CI 1.35–7.20)) and vascular events (HR 2.05, 95% CI 1.21–3.47). Advanced age, male gender, and ischemic stroke involving the entire anterior circulation raised the likelihood for death. We conclude that the presence of VBC in patients with ischemic stroke is a short- and long-term prognostic factor for stroke recurrence and subsequent manifestation of acute vascular disease. Further understanding of the pathophysiology of VBC is warranted.

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.

Spotty Calcium on Cervicocerebral Computed Tomography Angiography Associates With Increased Risk of Ischemic Stroke

Background and Purpose- Cervicocerebral vascular calcification on computed tomography angiography is a known sign of advanced atherosclerosis. However, the clinical significance of calcification pattern remains unclear. In this study, we aimed to investigate the potential association between spotty calcium and acute ischemic stroke. Methods- This study included patients with first-time nonlacunar ischemic stroke (N=50) confirmed by brain magnetic resonance imaging or nonenhanced head computed tomography, as well as control subjects with asymptomatic carotid atherosclerosis (N=50) confirmed by carotid ultrasonography. Subjects in both groups underwent contrast-enhanced cervicocerebral computed tomography angiography within a week after the initial imaging examination. Spotty calcification was evaluated at 11 arterial segments commonly affected by atherosclerosis along the carotid and vertebrobasilar circulation. Statistical analysis was performed comparing the frequency and spatial pattern of spotty calcification between the 2 groups. Results- Spotty calcification in the Stroke group was markedly more prevalent than that in the Control group (total SC count: 8.74±4.96 versus 1.84±1.82, P<0.001). The odds ratio (95% CI) for stroke was 2.49 (1.55-4.00) for spotty calcification at bilateral carotid bifurcation, 1.52 (1.13-2.04) at carotid siphon, and 1.98 (1.45-2.69) at all evaluated locations. A total number of 3 spotty calcifications were determined as the optimal cutoff threshold for increased risk of stroke. Spotty calcium showed significantly greater area under the receiver operating characteristics curve than total calcium volume irrespective of size (0.88 versus 0.77). Within the Stroke group, ipsilateral lateral side showed significantly more spotty calcium than the contralateral side (5.18±3.05 versus 3.56±2.67, P<0.001). Conclusions- Nonlacunar ischemia stroke was associated with markedly increased incidence of spotty calcification with a distinct spatial pattern on cervicocerebral computed tomography compared with subclinical atherosclerosis, suggesting the potential role of spotty calcification for improving the risk stratification for ischemic stroke.

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.

Detection of vessel wall calcifications in vertebral arteries using susceptibility weighted imaging

PURPOSE

Calcification of the brain supplying arteries has been linked to an increased risk for cerebrovascular disease. The purpose of this study was to test the potential of susceptibility weighted MR imaging (SWMR) for the detection of vertebral artery calcifications, based on CT as a reference standard.

METHODS

Four hundred seventy-four patients, who had received head CT and 1.5 T MR scans with SWMR, including the distal vertebral artery, between January 2014 and December 2016, were retrospectively evaluated and 389 patients were included. Sensitivity and specificity for the detection of focal calcifications and intra- and interobserver agreement were calculated for SWMR and standard MRI, using CT as a standard of reference. The diameter of vertebral artery calcifications was used to assess correlations between imaging modalities. Furthermore, the degree of vessel stenosis was determined in 30 patients, who had received an additional angiography.

RESULTS

On CT scans, 40 patients showed a total of 52 vertebral artery calcifications. While SWMR reached a sensitivity of 94% (95% CI 84-99%) and a specificity of 97% (95% CI 94-98%), standard MRI yielded a sensitivity of 33% (95% CI 20-46%), and a specificity of 93% (95% CI 90-96%). Linear regression analysis of size measurements confirmed a close correlation between SWMR and CT measurements (R ² = 0.74, p < 0.001). Compared to standard MRI (ICC = 0.52; CI 0.45-0.59), SWMR showed a higher interobserver agreement for calcification measurements (ICC = 0.84; CI 0.81-0.87).

CONCLUSIONS

For detection of distal vertebral artery calcifications, SWMR demonstrates a performance comparable to CT and considerably higher than conventional MRI.

Treatment and imaging of intracranial atherosclerotic stenosis: current perspectives and future directions

BACKGROUND AND PURPOSE

Intracranial atherosclerosis is a common cause of stroke worldwide. It results in ischemic stroke due to different mechanisms including artery-to-artery embolism, in situ thrombo-occlusion, occlusion of perforating arteries, and hemodynamic failure. In this review, we present an overview of current treatment and imaging modalities in intracranial atherosclerotic stenosis.

METHODS

PubMed was searched for relevant articles in English that evaluated the treatment and imaging of intracranial atherosclerotic stenosis (ICAS).

RESULTS

Aggressive medical management, consisting of dual antiplatelet therapy and intensive risk factor management, is important in patients with ICAS because of a substantial risk of recurrent stroke, approximately 20% in the first year, in patients on aspirin or warfarin alone. Recent trials have suggested that, aggressive medical therapy results in better outcome as compared with intracranial stenting. However, the question remains what the optimal treatment strategy would be in patients with recurrent strokes in the setting of failed aggressive medical therapy. Moreover, controversy exists whether a subgroup of patients with symptomatic ICAS could benefit from intracranial stenting if selection is based on radiological evidence of hemodynamic failure. With regard to imaging, transcranial Doppler ultrasound and magnetic resonance angiography are useful screening tests for exclusion of ICAS, but need confirmation by other imaging modalities when stenosis is suggested. Computed tomography angiography has a high positive and negative predictive value for detection of intracranial luminal stenosis of 50% or higher, but performs worse than digital subtraction angiography with regard to establishing the exact degree of luminal stenosis. Novel imaging techniques including high-resolution CT and MRI better identify plaque characteristics than conventional imaging methods.

CONCLUSIONS

Currently, aggressive medical management remains the standard of care for patients with ICAS. Further research is needed to identify high-risk subgroups and to develop more effective treatments for ICAS patients.

Age and gender related prevalence of intracranial calcifications in CT imaging; data from 12,000 healthy subjects

PURPOSE

Location and extent of intracranial calcifications have been detected accurately with the use of CT technology and since, many clinical or pathological entities have been linked to these calcifications. Our purpose is to provide data regarding the prevalence of calcifications in various locations in brain.

MATERIAL AND METHODS

We retrospectively examined 11,941 subjects who underwent non-contrast enhanced brain CT examination. We determined the prevalence of choroid plexus, pineal gland, habenula, dura mater, basal ganglia and vascular calcifications.

RESULTS

Of 11,941 subjects, 70.2% had choroid plexus calcifications. Calcifications were most frequently seen in pineal gland and 71.6% of the study population had pineal calcifications. Habeluna and dural calcifications were present in 19.2% and 12.5% of the population respectively. Basal ganglia calcifications and vascular calcifications only constituted 1.3% and 3.5% of the study population respectively. Male dominance was present in all calcification types except basal ganglia calcifications.

CONCLUSIONS

Showing associations and dissociations from the literature, our study provides a baseline data regarding the prevalence of various types of intracranial calcifications.

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.

Intracranial Carotid Calcification on Cranial Computed Tomography: Visual Scoring Methods, Semiautomated Scores, and Volume Measurements in Patients With Stroke

Supplemental Digital Content is available in the text.

Intracranial internal carotid artery calcification is associated with cerebrovascular risk factors and stroke, but few quantification methods are available. We tested the reliability of visual scoring, semiautomated Agatston score, and calcium volume measurement in patients with recent stroke.

The predictive value of arterial and valvular calcification for mortality and cardiovascular events

A review of the predictive ability of arterial and valvular calcification has shown an additive effect of calcification in more than 1 location in predicting mortality and coronary heart disease, with mitral annual calcification being a particularly strong predictor. In individual arteries and valves there is a clear association between calcification presence, extent and progression and future cardiovascular events and mortality in asymptomatic, symptomatic and high risk patients, although adjustment for calcification in other arterial beds generally renders associations non-significant. Furthermore, in acute coronary syndrome, culprit plaque is normally not calcified. This would tend to reduce the validity of calcification as a predictor and suggest that the association with cardiovascular events and mortality may not be causal. The association with stroke is less clear; carotid and intracranial artery calcification show little predictive ability, with symptomatic plaques tending to be uncalcified.

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.

Calcifications of vertebrobasilar arteries on CT: detailed distribution and relation to risk factors in 245 ischemic stroke patients

INTRODUCTION

Intracranial atherosclerosis is responsible for a substantial proportion of strokes worldwide but its detailed morphology in the vertebrobasilar arteries (VBA) is unknown.

SUBJECT AND METHODS

Cases with ischemic strokes were retrospectively sought from the hospital database. Native CT scans were assessed for vessel area and intracranial artery calcifications (ICACs) in VBA. The calcifications were classified as focal (FCs), crescent, and circular.

RESULTS

245 patients (mean age: 77.1 ± 10.2 years, 57.6% females) had visible ICACs. Calcifications were found in 75.9%, 63.3%, and 17.1% in the left vertebral artery (LVA), the right vertebral artery (RVA), and the basilar artery (BA), respectively. FCs were present in 91.0%, 90.3%, and 100.0%; crescents in 30.3%, 29.0%, and 7.1%, and circulars in 6.4%, 4.8%, and 0.0% ) and 46 (27.4%) for RVA and LVA, respectively. Risk factors associated with vertical dispersion of ICACs were male gender (OR : 2.69, 1.38-5.28) and diabetes of the RVA, LVA, and BA, respectively. FCs in dorsolateral quadrant were least prevalent in both vertebral arteries (VAs): 46 (29.8%(OR : 2.28, 1.04-4.99).

CONCLUSIONS

FCs in VAs are least prevalent in dorsolateral quadrants. The vertical dispersion of ICACs seems to be associated with the male gender and diabetes.

Calcified embolism: a rare cause of cerebral infarction

Calcified cerebral emboli (CCE) are a rare cause of stroke and these emboli can be identified on a CT scan of the brain performed for the initial evaluation of stroke. In this report we present a patient who developed a CCE following cardiac catheterisation that lodged in the left middle cerebral artery with resultant right hemiparesis and aphasia. The calcified embolus was seen on CT but could not be identified on MRI. Predisposing factors for CCE include angiography and valve or vessel wall calcification. The natural history and response to standard therapy in patients with CCE as compared with stroke of other aetiologies have not been studied until now. Increased awareness and ability to identify calcified emboli will help us to have an improved understanding of strokes resulting from CCE.

Cerebral artery calcification in patients with acute cerebrovascular diseases: determinants and long-term clinical outcome

BACKGROUND AND PURPOSE

Coronary artery calcium is an independent predictor of all-cause mortality. We sought to examine the determinants of intracranial cerebral artery calcification (CAC) and its association with long-term outcome in a large prospective cohort of stroke patients.

METHODS

Consecutive patients hospitalized because of acute stroke (ischaemic and intracerebral hemorrhage) or TIA throughout a large medical center were systematically assessed and followed up for 1 year. Intracranial CAC was assessed from baseline brain CT blinded to clinical data. Patients were categorized to no, mild, and severe CAC according to their total CAC score. Determinants of CAC were studied with logistic regression analysis. Risk of death, Barthel Index ≤ 60 or death and living in a nursing facility or death were assessed.

RESULTS

  Amongst 1049 patients (mean age: 70 ± 13 years, 59% males) CAC was present in 727 (69%) patients. The main determinants of CAC were increasing age (OR 1.4, 95% CI 1.3-1.6, per 5 years), diabetes (OR: 2.1, 1.4-3.0), smoking (1.4, 1.0-2.2), hypertension (1.4, 1.0-2.1), and prior coronary heart disease (1.9, 1.3-2.9). CAC was associated with mortality and poor outcome amongst patients with ischaemic stroke; however, after adjusting for age and stroke severity, no significant association was observed. In patients with intracerebral hemorrhage, outcomes were not related to CAC.

CONCLUSIONS

  Intracranial CAC is highly prevalent in patients with acute stroke and its main determinants are older age, diabetes, smoking, hypertension, and prior coronary heart disease. Associations between CAC and mortality or poor functional outcome in the first year after ischaemic stroke are mainly age- and stroke severity-driven.

Prevalence of intracranial artery calcification in hemodialysis patients--a case-control study

BACKGROUND

Intracranial artery calcification has been reported to be an independent risk factor for ischemic stroke. Also, existence of a positive correlation has been reported between the presence of arterial calcification and that of ischemic changes in the area supplied by such arteries. While intracranial artery calcification has frequently been observed on computed tomographic (CT) images of the brain in hemodialysis patients, its prevalence has not been reported previously. We investigated our hemodialysis outpatients to determine the prevalence of intracranial artery calcification in these patients in comparison with that in healthy controls.

METHODS

Brain CT examinations were performed in 107 patients under maintenance hemodialysis therapy. For comparison, 43 representatives of the general population who underwent a brain CT examination as part of a health checkup were also studied as control subjects.

RESULTS

Intracranial calcifications were more frequently found among hemodialysis patients (87.9%) than among control subjects (53.5%, P = 0.0003), and the prevalences of calcification in each of the intracranial arteries in the two groups were as follows: vertebral artery (65.5% vs. 25.6%, P = 0.0002), internal carotid artery (62.1% vs. 18.6%, P < 0.0001), basilar artery (34.5% vs. 34.9%, ns), anterior cerebral artery (0 vs. 2.3%, ns), middle cerebral artery (24.1% vs. 20.9%, ns), and posterior cerebral artery (5.2% vs. 4.7%, ns).

CONCLUSIONS

A much higher rate of intracranial artery calcification was observed in hemodialysis patients than in the general population, and the most frequently involved sites of calcification in these patients were the relatively large intracranial arteries.

Prevalence and Calcification of Intracranial Arterial Stenotic Lesions as Assessed With Multidetector Computed Tomography Angiography

Background and Purpose—

Intracranial arterial stenosis (ICAS) in patients with recent ischemic stroke is associated with a high risk of recurrent stroke. More insight into the pathophysiology of ICAS could help identify patients at high risk requiring more aggressive secondary prevention. We evaluated the prevalence, distribution, calcification, and the risk factors predisposing ICAS in a European stroke population.

Methods—

Consecutive patients with a transient ischemic attack or ischemic stroke (n=786) were evaluated for the presence and distribution of ICAS (≥30% luminal narrowing) by CT angiography. ICAS were categorized as symptomatic or asymptomatic, and the presence of calcification was assessed. The association of traditional cerebrovascular risk factors and the erythrocyte sedimentation rate with ICAS was analyzed.

Results—

In 178 of 786 patients (23%), 288 ICAS were observed. Most stenoses (n=194/288; 67%) were located in the posterior circulation arteries. In 59 of 786 patients (8%), ICAS were considered symptomatic. ICAS in the basilar artery and arteries beyond the circle of Willis were mainly noncalcified. In addition to age, gender, and several traditional cerebrovascular risk factors, erythrocyte sedimentation rate was independently associated with the presence of ICAS (OR, 1.20; 95% CI, 1.06–1.36) and with the presence of noncalcified ICAS in particular (OR, 1.20; 95% CI, 1.05–1.37).

Conclusions—

ICAS was observed in a noteworthy number of European stroke patients. Particularly, the majority of ICAS was observed in the posterior circulation, possibly conferring worse prognosis. ICAS in distal arteries were mainly noncalcified. Association of noncalcified ICAS and erythrocyte sedimentation rate may indicate a prominent role for inflammatory factors in intracranial atherosclerotic disease.

Intracranial artery calcification in hemodialysis patients

Intracranial artery calcification is an independent risk factor for ischemic stroke, and while it is frequently observed on computed tomographic images of the brain in hemodialysis patients, its distribution has not been well studied. Fifty patients on maintenance hemodialysis were enrolled in this study. We divided the patients with intracranial artery calcification into two groups according to the duration of maintenance hemodialysis and compared the frequency of intracranial calcification of each of the intracranial arteries between the two groups. Intracranial artery calcification was found in 36 of the 50 hemodialysis patients. Among the 36 patients with intracranial artery calcification, the prevalence of calcification of each of the arteries was as follows: vertebral artery, 58.3%; internal carotid artery, 61.1%; basilar artery, 41.7%; anterior cerebral artery, 16.7%; middle cerebral artery, 30.6%; posterior cerebral artery, 8.3%. The prevalence of calcification of each of the intracranial arteries did not differ significantly between the patients with a hemodialysis duration of more than 20 years and those less than 20 years. The most frequently involved site of calcification was the internal carotid artery. The prevalence of calcification of the other intracranial arteries, particularly of the basilar artery, were relatively high. The prevalence of calcification of each of the intracranial arteries did not differ significantly between the patients with a hemodialysis duration of more than 20 years and less than 20 years.

Computed tomography evaluation of intracranial atherosclerosis in Chinese patients with transient ischemic attack or minor ischemic stroke--its distribution and association with vascular risk factors

OBJECTIVES

Intracranial atherosclerosis has been suggested to be common in Asians. We apply a semi-quantitative CT scoring system to evaluate the degree of intracranial atherosclerotic calcification and determine its distribution, severity, and the associated risk factors. The clinical outcome of these patients after a 3-year follow-up was also evaluated.

METHODS

Sixty consecutive patients diagnosed clinically to have either a transient ischemic attack (TIA) or minor ischemic stroke and underwent early computed tomographic angiography (CTA) were included into the prospective study. Two radiologists evaluated the axial CTA images for any calcification in the precavernous, cavernous and postcavernous segments of intracranial internal carotid artery (ICA), anterior, middle, and posterior cerebral as well as vertebrobasilar arteries, based on a standard CT scoring system for extent (0-4) and thickness (0-4). The composite CT score for extent and thickness of these vascular segments or vessels were recorded for all patients. The worst site (highest composite score) was chosen as the marker of the degree of intracranial atherosclerosis of each patient. The patients were then classified into mild, moderate, and severe groups, according to a composite CT score of 0-2, 3-5, and 6-8, respectively. These findings were gathered with clinical parameters and outcome after a 3-year follow-up period and corresponding statistical analyses were conducted.

RESULTS

The most severely affected vessel was found to be intracranial internal carotid arteries, and severe, moderate, and mild atherosclerosis were present in 16 (26.67%), 30 (50%), and 14 (23.33%) patients, respectively. Using multiple logistic regression analysis, diabetes mellitus (odds ratio = 10.6, P value = .004), and age (odds ratio = 1.07, P value = .02) were found to be significant risk factors for severe intracranial atherosclerosis. Two patients in the severe group, 3 patients in the moderate group, and 1 patient in the mild group were found to have stroke or TIA after a 3-year follow-up, but there was no significant difference among the 3 groups.

CONCLUSION

Significant intracranial atherosclerosis as determined by severe CT calcification was common in a cohort of Chinese patients with TIA and minor stroke. Age and diabetes mellitus were independent significant risk factors, and this CT calcification score might serve as an early indicator of intracranial atherosclerotic disease.

Incidental renal artery calcifications: a study of 350 consecutive abdominal computed tomography scans

BACKGROUND

Calcifications in arteries are thought to represent atherosclerosis.

METHODS

Consecutive abdominal tomographic scans performed during a 4-month period were evaluated and assessed for renal artery calcifications (RAC). Scans that showed calcifications were evaluated for renal artery narrowing and for various characteristics of the atherosclerotic plaque.

RESULTS

Of 350 consecutive examinees, 43% were men, 40% had hypertension and 38% had hypercholesterolaemia. The age was 61 +/- 13 years. Aortic calcifications were found in 54% and RAC in 102 (29%), of whom 53 had bilateral calcifications. Subjects with RAC were older, 72 +/- 6 versus 55 +/- 12 years. Adjusted odds ratios of RAC were 2.2 (95% CI 1.1-4.6) for male gender, 2.4 (1.2-4.8) for hypertension and 2.9 (1.4-5.8) for hypercholesterolaemia, whereas family history of hypertension was protective with 0.5 (0.3-0.9). All patients with calcified renal arteries had aortic calcifications, versus 35% of those without RAC. A significant correlation was found between the severity of calcifications and the degree of renal artery narrowing (r = 0.7), and also between the presence of bilateral calcifications and a high-grade narrowing.

CONCLUSIONS

RAC strongly relates to atherosclerosis. Calcifications and artery narrowing may have a role in the pathogenesis of hypertension. Bilateral calcifications suggest atherosclerotic renal artery stenosis.

High prevalence of intracranial artery calcification in stroke patients with CKD: a retrospective study

BACKGROUND AND OBJECTIVES

Intracranial artery calcification (IAC) is frequently observed on brain computed tomography (CT) scans in stroke patients. This retrospective study was designed to determine the prevalence, risk factors, and clinical relevance of IAC in a cohort of patients with ischemic stroke.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We included all eligible patients admitted to Amiens University Hospital for acute ischemic stroke between January and December 2006 and assessed using 64-slice multidetector-row CT (n = 340). Patients were classified according to the presence or absence of IAC in the internal carotid arteries, middle cerebral arteries, vertebral arteries, and basilar artery. GFR was estimated using the MDRD equation. Chronic kidney disease (CKD) was defined as a GFR < 60 ml/min/1.73 m(2). We also studied a control group of patients admitted for neurologic diseases other than stroke.

RESULTS

Two hundred fifty-nine stroke patients (76.2%) displayed IAC, which was independently associated with carotid atherosclerosis > 50%, age, and GFR. One hundred three nonstroke patients (60.2%) had IAC, with age, arterial hypertension, and GFR as independently associated factors. For all patients taken together, age, arterial hypertension, stroke, and GFR were independently associated with IAC.

CONCLUSION

These results confirm the high prevalence of IAC in patients with and without ischemic stroke and show for the first time that IAC is associated with the presence of CKD in these patients. The frequency of IAC was significantly higher in stroke patients than in nonstroke patients. The association between IAC and stroke outcome requires further investigation.

Intracranial internal carotid artery calcifications: association with vascular risk factors and ischemic cerebrovascular disease

BACKGROUND AND PURPOSE

Atherosclerotic calcifications are present not only in the extracranial carotid bifurcation but also in the intracranial part of the internal carotid artery. We assessed the association between intracranial internal carotid artery calcifications and cardiovascular risk factors in patients with ischemic cerebrovascular disease and the association between calcifications and the presence of this disease.

MATERIALS AND METHODS

Patients undergoing multidetector CT (MDCT) angiography of the carotid arteries for assessment of stenosis degree were included in the study. A semiautomatic custom-made system to quantify calcifications was developed. The associations between the volume of calcifications and cardiovascular risk factors and the type of ischemic cerebrovascular symptoms were assessed with logistic regression.

RESULTS

MDCT angiography was performed in 406 patients (age, 62 +/- 14 years; 242 men). Men had a significantly higher calcification volume (66 mm(3)) than women (33 mm(3)). Calcification volume was positively associated with age in both men and women. Smoking, hypercholesterolemia, and a history of cardiac disease were independently related to the presence of calcifications. A history of cardiac disease and ischemic cerebrovascular disease were independently related to the volume of calcifications. No association was found between calcifications and the presence or type of ischemic cerebrovascular disease in the vascular territory of the intracranial internal carotid artery.

CONCLUSIONS

Calcifications were associated with higher age and male gender. The presence and volume of calcifications were independently associated with cardiovascular risk factors. Calcifications were not related to the presence or type of ischemic cerebrovascular disease.

[Clinical and pathological significance of carotid siphon calcification observed on bone condition of brain CT]

PURPOSE

On plain brain computed tomography (CT), it is difficult to evaluate stenosis of internal carotid artery (ICA) because ICA is surrounded by structures, even though we can observe calcification of carotid siphon in some patients by using bone condition. However the pathologic significance has not been well known. We studied the pathologic significance of carotid siphon calcification observed on bone condition of brain CT.

METHODS

A total of 112 patients who were diagnosed or suspected as cerebrovascular diseases were registered. We classified the calcification into four levels (none, mild, moderate, severe) based on the degree of calcification. Then we compared it with the degree of stenosis of carotid siphon seen on brain magnetic resonance angiography (MRA) and with max intima-medial thickness (IMT) from common carotid artery (CCA) to ICA on carotid ultrasonography.

RESULT

The mean +/- standard deviation of max IMT to none, mild, moderate and severe in the degree of calcification were 1.03 +/- 0.64 (0.4-2.8), 1.65 +/- 0.83 (0.5-4.1), 2.03 +/- 0.83 (0.8-4.1) and 2.81 +/- 1.15 (0.7-6.5) mm, respectively. The calcification on brain CT significantly correlated with the degree of stenosis on brain MRA and with max IMT on carotid ultrasonography.

CONCLUSION

The calcification of carotid siphon on bone condition of brain CT correlated with stenosis of the same portion and atherosclerosis of CCA bifurcation. Recently, on DICOM viewer, clinicians can convert plain condition into bone condition on brain CT due to popularization of PACS. We should pay attention to calcification of carotid siphon in patients with ischemic cerebrovascular diseases because we can estimate the atherosclerosis of both carotid siphon and CCA bifurcation easily and immediately.

Intracranial artery calcification: a newly identified risk factor of ischemic stroke

BACKGROUND AND PURPOSE

Calcification in cerebral arteries is understudied, although frequently observed on computed tomography of the brain (CT brain). We aimed to assess the incidence of intracranial artery calcification in ischemic stroke patients and to evaluate its correlation with ischemic stroke.

METHODS

Our study included ischemic stroke patients and age-gender-matched nonischemic stroke patients referred for CT brain.

RESULTS

One hundred and seventy-five ischemic stroke patients and 182 controls were enrolled. The highest prevalence of calcification was seen in intracranial internal carotid artery (IICA) (80.4%), and less commonly in the vertebral artery (35.6%). There was a higher prevalence of intracranial artery calcification in ischemic stroke patients than controls (92.6% vs. 76.4%, P < .001). Hypertension (OR = 2.056, 95% CI: 1.129 approximately 3.745), diabetes (OR = 2.483, 95% CI: 1.233 approximately 5.001), smoking (OR = 2.844, 95% CI: 1.542 approximately 5.243), intracranial artery calcification (OR = 3.172, 95% CI: 1.252 approximately 8.036), hyperlipidemia (OR = 6.714, 95% CI: 3.302 approximately 13.650), and atrial fibrillation (OR = 7.941, 95% CI: 2.790 approximately 22.599) were found to be independently associated with ischemic stroke.

CONCLUSIONS

We demonstrated a higher incidence of intracranial artery calcification in ischemic stroke patients. Besides traditional risk factors, intracranial artery calcification was found to be an independent risk factor of ischemic stroke.

Intracranial carotid calcification on CT images as an indicator of atheromatous plaque: analysis of high-resolution CTA images using a 64-multidetector scanner

PURPOSE

Intracranial arterial wall calcifications are frequently observed on routine head computed tomography (CT) images. The purpose of this study was to evaluate whether calcification of the intracranial carotid artery on CT images could predict atheromatous plaque and luminal stenosis.

MATERIALS AND METHODS

A total of 259 patients were examined using three-dimensional CT angiography using high-resolution 64 detector scanners. We examined patients from the petrous portion to the top of the internal carotid arteries. We evaluated the existence of calcification and atheromatous plaque based on our criteria retrospectively. The thickness of calcification was measured in each vessel, and the shape of calcification was classified into three types.

RESULTS

There was low correlation between the thickness of the calcification and luminal stenosis, but the shape of the calcification corresponded well to the stenosis. The population of patients with >50% stenosis of the intracranial carotid artery differed statistically significantly for each calcification shape. There was a high negative predictive value (97.7%) in the correlation between the existence of calcification and atheromatous plaque on the multidetector CT images.

CONCLUSION

Calcification of the intracranial carotid artery on CT images shows a high negative predictive value for the existence of atheromatous plaque in the same artery. The thickness of the calcification did not correlate well with luminal stenosis, but its shape seemed to predict luminal stenosis.

Evaluation of arteriosclerotic changes in the intracranial carotid artery using the calcium score obtained on plain cranial computed tomography scan: Correlation with angiographic changes and clinical outcome

PURPOSE

This study evaluated the correlation between quantified calcification of the carotid siphon and arteriosclerotic changes on angiography as well as clinical outcome. We used the calcium score obtained from intracranial carotid arteries viewed on plain CT.

METHOD/MATERIALS

We examined carotid siphons of 72 consecutive patients who had undergone both plain CT and angiography of the brain. We calculated calcium scores of the carotid siphon. Arteriosclerotic changes on angiography were categorized as "smooth," "irregular," or "stenosis." We assessed the correlation between the scores and arteriosclerotic changes both in the carotid siphon and the bifurcation. We reviewed clinical records approximately 2 years after examination and evaluated the scores of patients who did and did not experience cerebral strokes.

RESULTS

In the evaluation between angiographic findings of siphon and calcium score of the siphon, there were statistically significant differences between the "smooth" and "irregular", "irregular" and "stenosis" and the "smooth" and "stenosis". In the evaluation between angiographic findings of bifurcation and the score of the siphon, a statistically significant difference was only seen between "smooth" and "stenosis". No significant differences in calcium scores were observed between patients groups who did or did not experience a cerebral stroke.

CONCLUSIONS

There were a positive correlation between calcium scores on CT and angiographic changes of arteriosclerosis in the siphon as well as bifurcation, indicating angiographic changes can be predicted using calcium scores. However, the degree of calcification in the siphon cannot be used to predict the possibility of a future cerebral stroke.

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

BACKGROUND

Intracranial artery calcification is common but the prevalence and determinants are not well established. We aim to describe the prevalence and location of calcification in intracranial arteries according to brain multi-detector-row computed tomography (MDCT) images, and to investigate its correlation with potential risk factors.

METHODS

We studied consecutive men and women referred for brain CT in December 2004. All patients received a questionnaire regarding their medical history related to atherosclerosis, including traditional risk factors of atherosclerosis, serum chemistry values and inflammatory markers. All CT examinations were done with a 16-slice MDCT and the severity of intracranial artery calcification was categorized.

RESULTS

Four hundred and ninety patients aged 1.4-101 years (62.92+/-19.04; mean+/-SD) were included in our study. There were 340 patients (69.4%) who had intracranial artery calcification. The highest prevalence of intracranial artery calcification was seen in the internal carotid artery (60%), followed by vertebral artery (20%), middle cerebral artery (5%) and basilar artery (5%). Patients with calcification were significantly older than those without calcification (p<0.001). A significantly higher prevalence of calcification was present among patients with hypertension (p<0.001), diabetes (p<0.001), renal failure (p<0.05), atrial fibrillation (p<0.05), smoking (p<0.05), hyperlipidemia (p<0.001), ischemic heart disease (p<0.05) and ischemic stroke (p<0.001). Mean values of serum phosphate, serum urea and CRP level were also significantly higher in patients with intracranial artery calcification (p<0.05, respectively), and there was a trend that patients with intracranial calcification had a higher white blood cell count (p=0.070). Stepwise multiple logistic regression showed age (RR=2.795 per 10 years), a history of ischemic stroke (RR=3.915), and white blood cell count (RR=1.107) to be independently associated with intracranial artery calcification.

CONCLUSIONS

Calcification of the intracranial arteries is associated with age, history of ischemic stroke and white blood cell count. Further prospective studies to investigate the clinical significance of intracranial artery calcification are needed.