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

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.

Intracranial Calcifications

Brain calcifications are a common radiographic finding. The pathogenesis is diverse and ranges from benign physiological calcifications to a variety of pathological disorders. Whereas certain calcifications are considered an incidental finding, their presence can sometimes be crucial in making a specific diagnosis. Several pathological conditions affecting the brain parenchyma are associated with calcifications and their recognition and location might help in narrowing the differential. Knowledge of physiological calcifications is essential to avoid misinterpretation. This review illustrates a broad spectrum of CNS disorders associated with calcifications, and tries to highlight the salient radiological findings.

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.

Presence of intracranial artery calcification is associated with mortality and vascular events in patients with ischemic stroke after hospital discharge: a cohort study

BACKGROUND AND PURPOSE

Although intracranial artery calcification (IAC) has been reported to be a risk factor for ischemic stroke, the prognostic implications of IAC in stroke outcome are unknown. The purpose of this study was to determine the association between IAC and risk of vascular events and death in patients with stroke after hospital discharge.

METHODS

All patients with ischemic stroke over a 1-year period were included (n=302). IAC, assessed by multidetector CT, was defined as hyperdense foci (peak density>130 Hounsfield units) and assessed in the 7 major cerebral arteries. The IAC scores ranged from 0 (no calcification) to 7. Follow-up information on major clinical events (including fatal or nonfatal ischemic stroke, cardiac and peripheral artery events, and all-cause death) was obtained by means of a structured phone interview.

RESULTS

IAC was present in 260 patients (83%). With a mean follow-up of 773±223 days, 88 major clinical events occurred in 67 patients (22%): 45 new ischemic vascular events (ischemic stroke: n=22; cardiac event: n=15; peripheral artery event: n=8) and 43 deaths from any cause. Patients with the highest IAC scores had significantly higher rates of death and vascular events than those with the lowest IAC scores (log rank test, P=0.029). In the Cox proportional hazards regression model, the IAC score was significantly associated with major clinical events (hazard ratio, 1.34; 95% CI, 1.11-1.61; P=0.002).

CONCLUSIONS

In patients with ischemic stroke, IAC detection may constitute a simple marker of a high risk of future major clinical events.

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.

Differing risk factors and outcomes in ischemic stroke subtypes: focus on lacunar stroke

Lacunar stroke has been a recognized stroke subtype for many years but its pathophysiology remains unknown, so prevention and treatment are suboptimal. Most lacunar strokes result from an intrinsic cerebral small vessel disease, probably part of a systemic disorder. Hypertension, diabetes and other vascular risk factors (but not atrial fibrillation and ipsilateral carotid stenosis) are equally common in lacunar as in large artery atherothromboembolic stroke, which, together with other factors, suggests that the patient’s response to vascular risk factors, not the vascular risk factors per se, determines whether they develop small vessel or large artery stroke. Inflammation and endothelial failure are probably involved in the pathogenesis of lacunar stroke, but their role needs to be clarified. The cerebral venules as well as arterioles are abnormal in this condition. The disorder may not be primarily ischemic; instead, arteriolar thrombosis may be a late-stage phenomenon secondary to chronic arteriolar wall damage resulting from leakage of plasma components across the BBB. Accurate diagnosis of lacunar stroke, avoiding risk factor-based classifications, is required to underpin future research.

Carotid and cerebrovascular disease in symptomatic patients with type 2 diabetes: assessment of prevalence and plaque morphology by dual-source computed tomography angiography

Background

Plaque morphology directly correlates with risk of embolism and the recently developed dual-source computed tomography angiography (DSCTA) may help to detect plaques more precisely. The aim of our study was to evaluate the prevalence and morphology of carotid and cerebrovascular atherosclerotic plaques in patients with symptomatic type 2 diabetes mellitus (DM) by DSCTA.

Methods

From July 2009 to August 2010, DSCTA was prospectively performed in 125 consecutive patients with symptomatic type 2 DM. We retrospectively analyzed plaque type, distribution, and extensive and obstructive natures were determined for each segment for all patients.

Results

Atherosclerotic plaques were detected in 114 (91.2%) patients. Relatively more noncalcified (45%) and calcified (39%) plaques and less mixed (16%) plaques were observed (p < 0.001). Noncalcified plaques were found mainly in the intracranial arteries (81.8%), mixed plaques in the intracranial arteries (25.2%) and intracranial internal carotid artery (ICA) (56.1%). Calcified plaques were found mainly in the intracranial ICA (65.9%) and extracranial arteries (28.2%) (for all, p < 0.001). Extension of plaques from the 1^st to 5^th segments was observed in 67 (58.8%) patients and from the 6^th to 10^th segments in 35 (30.7%) patients. The most common site of all detected plaques was the cavernous segment. Regarding stenosis, there were significantly more nonobstructive than obstructive stenosis (91% vs. 9%, p < 0.001).

Conclusion

DSCTA detected a high prevalence of plaques in patients with symptomatic type 2 DM. A relatively high proportion of plaques were noncalcified, as well as with nonobstructive stenosis. The distribution of plaques was extensive, with the cavernous portion of ICA being the most common site.

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.

Correlation between carotid intimal/medial thickness and atherosclerosis: a point of view from pathology

A widely adopted surrogate for predicting rates of cardiovascular events involves measure of carotid intimal-medial thickness (CIMT) by B mode ultrasound, a technique available since the mid 1980s. The value of this modality remains in its ability to noninvasively assess cardiovascular risk beyond traditional factors identified by the Framingham risk score, and it is among the few available techniques for monitoring the effectiveness of pharmacotherapy on plaques. There are, however, existing limitations to this methodology. Perhaps the most important distinction is that IM thickness measurements are generally acquired in the common carotid artery, whereas advanced atherosclerotic disease occurs predominantly downstream in the internal carotid. Moreover, primary contributors to IM thickening are age and hypertension, which do not necessarily reflect the atherosclerotic process. Initiation of disease-related plaques begins as what is referred to as pathological intimal thickening; lesions characterized by the formation of lipid pools in the absence of a necrotic core. The eventual development of a necrotic core, however, is considered a key indicator of significant plaque advancement and recognized feature of lesion vulnerability. Necrotic cores are thought to arise from macrophage infiltration of lipid pools followed by secondary necrosis where defective clearance of debris, tissue disruption proteases, and intraplaque hemorrhage, likely contribute to its enlargement. Therefore, one of the primary limitations to CIMT is its inability to distinguish lesions with a necrotic core. Moreover, in most cases measures of plaque area or volume are generally considered better predictors of an inflammatory process consistent with atherosclerotic disease rather than intimal medial thickness.

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.

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.

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.