Correlation between carotid bifurcation calcium burden on non-enhanced CT and percentage stenosis, as confirmed by digital subtraction angiography

Relationship Between Carotid Artery Angle and Plaque Morphology in Acute Cerebral Infarction Patients

BACKGROUND

High-resolution magnetic resonance imaging (HRMRI) can be used to clearly distinguish the luminal structure of the carotid artery (CA); measure the lumen, vessel wall, and total blood vessel area; and accurately describe the morphologic features of plaques.

METHODS

This study used HRMRI to investigate the relationship between geometric features and volume and composition of carotid atherosclerotic plaques. Patients (n=81) who had experienced acute cerebral infarction (CI) within 7±3 days before admission to the Neurology Department of Beijing Tiantan Hospital between November 2011 and June 2012 were enrolled in the study. CA HRMRI was performed to analyze the geometry and morphology of plaques in 160 blood vessels.

RESULTS

The median left and right internal carotid artery angles (ICAAs) were 32.79 and 31.00 degrees, respectively. Aside from the nonplanar external CA angle, plaque volume and angles did not differ significantly between the left and right sides. Age ( B =3.77; P =0.03) and nonplanar ICAA ( B =4.70; P =0.01) were predictors of left but not right carotid plaque volume. ICAA and bifurcation angle did not predict plaque volume.

CONCLUSIONS

In this study, CA morphology in acute stroke patients is not associated with plaque volume or composition, but age and nonplanar ICAA can predict left carotid plaque volume.

Intra-plaque calcium and its relation with the progression of carotid atheromatous disease

BACKGROUND

Calcification and progression of atheromatous disease (AD) both have been independently related with the risk of stroke. However, the link between the two phenomena is still unclear. The main objective of this study was to analyze the temporal evolution of Ca content of carotid atheromatous plaques and its relation with the progression of carotid AD using quantitative CT Angiography (CTA).

METHODS

Forty-three asymptomatic patients with stenosis of the internal carotid artery (ICA)>50% completed the study. Contrast mold volume and calcium (Ca) content by quantitative CTA and Modified Agatston Score (Ca volume x radiological density) were assessed at baseline and after 12±2 months. Biochemical parameters, including main markers of Ca/Phosphorus (P) metabolism, were determined.

RESULTS

CTA measurement showed an increase of volumetric stenosis (volume decrease of the contrast mold), compared to baseline (475.45 (155.6) mm3 x U.H vs 501.3 (171.9) mm3 x U.H; p=0.04) as well as an increase of intra-plaque Ca (64.58 (57.8) mm3x U.H. vs 56.8 (52.3) p=0.002). An inverse correlation between baseline Ca content and volumetric stenosis progression (r= - 0.481; p<0.001), as well as between the increase of carotid Ca and plasma levels of vitamin D (r= 0.4; p=0.025) were also found. Multiple regression analysis found a model with baseline intra-plaque Ca, adjusted by body mass index (BMI) as most predictive of carotid AD progression.

CONCLUSIONS

These results suggest that a higher content of Ca confers greater stability against the progression of carotid AD and, eventually, its ability to generate symptomatology.

Imaging Approaches to the Diagnosis of Vascular Diseases

PURPOSE OF REVIEW

Vascular imaging is a complex field including numerous modalities and imaging markers. This review is focused on important and recent findings in atherosclerotic carotid artery plaque imaging with an emphasis on developments in magnetic resonance imaging (MRI) and computed tomography (CT).

RECENT FINDINGS

Recent evidence shows that carotid plaque characteristics and not only established measures of carotid plaque burden and stenosis are associated independently with cardiovascular outcomes. On carotid MRI, the presence of a lipid-rich necrotic core (LRNC) has been associated with incident cardiovascular disease (CVD) events independent of wall thickness, a traditional measure of plaque burden. On carotid MRI, intraplaque hemorrhage (IPH) presence has been identified as an independent predictor of stroke. The presence of a fissured carotid fibrous cap has been associated with contrast enhancement on CT angiography imaging. Carotid artery plaque characteristics have been associated with incident CVD events, and advanced plaque imaging techniques may gain additional prominence in the clinical treatment decision process.

Assessment of relationship between extracranial and intracranial carotid calcifications-a retrospective cone beam computed tomography study

OBJECTIVES

Cone beam CT scans in current day dental practice are highly collimated yet involve areas along the course of the extracranial carotid artery. Detecting an extracranial carotid calcification on small volume scans leaves the dentist with two questions: whether the patient is likely to have intracranial carotid calcifications and whether the patient warrants further medical attention. This study aimed to assess the presence of intracranial carotid artery calcifications (ICAC) in the presence of extracranial carotid artery calcifications (ECAC).

METHODS

450 CBCT scans were retrospectively evaluated for ECAC and ICAC. Erby et al's classification was modified to classify calcifications as mild, moderate, and severe. The presence of ICAC when ECAC were present was evaluated in all three orthogonal planes. The risk of ICAC in the presence of ECAC was calculated as odds ratio and the association between the two was calculated using a χ² test.

RESULTS

The odds ratio for bilateral ICAC in the presence of bilateral ECAC was 15.09. The odds ratio for left ICAC/right ICAC in the presence of left/ right ECAC was 0.833 and 2.564, respectively. The number and severity of calcifications increased with age. The χ² test showed that there was a strong association (p < 0.001) between bilateral ECAC with bilateral ICAC.

CONCLUSIONS

The results of this group of patients showed that there is an increased presence of ICAC in the presence of ECAC.

Relationship Between Carotid Stenosis and Infarct Volume in Ischemic Stroke Patients

Background

Stroke is a serious health problem all over the world. Ischemia causes 85% of strokes and 75% of these ischemic strokes occur within the area supplied by the internal carotid artery (ICA).

Material/Methods

This study included 47 acute stroke patients who were in the large-artery atherosclerosis group according to Trial of ORG 10172 in Acute Stroke Treatment (TOAST) classification and who had an infarct in the area supplied by the internal carotid artery. We sought to determine whether there was a significant correlation between the infarct volume of the patients as measured by diffusion-weighted magnetic resonance imaging (DW MRI), their National Institutes of Health Stroke Scale (NIHSS), and degree of carotid stenosis as identified by carotid computed tomography angiography (CTA).

Results

A significant correlation was observed between the percentage of carotid artery stenosis and infarct volume (p<0.001). In addition, there was a significant positive correlation between the NIHSS and infarct volume; the correlation was of moderate strength (r=0.366, p=0.001).

Conclusions

Our findings indicate that the percentage of carotid artery stenosis could be useful in predicting the infarct volume of the stroke.

Distribution of calcification in carotid endarterectomy tissues: Comparison of micro-computed tomography imaging with histology

Background:

Calcification in atherosclerotic plaques has been viewed as a marker of plaque stability, but whether calcification accumulates in specific anatomic sites in the carotid artery is unknown. We determined the burden and distribution of calcified plaque in carotid endarterectomy (CEA) tissues.

Methods:

A total of 22 CEA tissues were imaged with high-resolution micro-computed tomography (micro-CT). Total plaque burden and total calcium score using the Agatston method were quantified. The Agatston score (AS) was also normalized for tissue size. Plaque and calcium distribution were analyzed separately for three CEA regions: common segment (CS), bulb segment (BS), and internal/external segments (IES).

Results:

The average CEA tissue length was 40.83 (interquartile range [IQR] 33.31–42.41) mm with total plaque burden of 103.45 (IQR: 78.84–156.81) mm3 and total AS of 38.58 (IQR 11.59–89.97). Total plaque volume was 21.02 (IQR: 14.47–25.42) mm3 in the CS, 37.89 (22.59–48.32) mm3 in the BS, and 54.05 (36.87–74.52) mm3 in the IES. Of the 22 tissues, 15 had no calcium in the CS compared with three in the bulb and two in the IES. Normalized calcified plaque was most prevalent in the BS, the IES and was least prevalent in the CS. The overall correlation of calcification between histology sections and matched micro-CT images was 0.86 ( p<0.001).

Conclusions:

Calcified plaque is heterogeneously distributed in CEA tissues with most in the bulb and IES regions. The amount of calcification in micro-CT slices shows a high correlation with matched histology sections.