Widening and Rotation of Carotid Artery with Age: Geometric Approach

Geometric changes and clinical risk factors from aortic arch to proximal internal carotid artery between normal subjects and moderate right carotid plaques

The anatomical features spanning from the aortic arch to the proximal carotid artery and the associated cardiovascular risks might significantly influence the development of right carotid plaque. Our research aimed to compare these anatomical and risk factors between individuals with no carotid plaque and those with moderate right-side carotid plaque within a Korean cohort. We conducted a retrospective, cross-sectional analysis involving 413 participants, categorized into a normal group (n = 339) and a right moderate carotid plaque group (defined as > 50% stenosis based on NASCET criteria) (n = 74). We collected data on cardiovascular risk factors and conducted laboratory tests. A 3D model of the carotid artery was constructed using cranio-cervical computed tomography angiography (CTA) data through semi-automated software. Measurements taken on this 3D model included the common carotid artery (CCA), internal carotid artery (ICA), external carotid artery (ECA), and carotid artery bifurcation (CAB) in terms of maximal vascular diameter, sectional area, angles of carotid bifurcation and ICA, and carotid tortuosity. When compared with the normal group, individuals in the right moderate carotid plaque group exhibited smaller angles at the carotid bifurcation, larger CCA diameter and sectional area (p < 0.01), advanced age, and a higher incidence of hypertension, diabetes, and stroke history (p < 0.05), along with reduced glomerular filtration rate (GFR) (p < 0.001). Multivariate analysis revealed that the sectional area of the bifurcation, calcification of the aortic bulb, and GFR were independently associated with the presence of right moderate carotid plaque (p < 0.01). Statistical analyses disclosed significant differences in both clinical risk factors and geometric changes in the region extending from the aortic arch to the proximal carotid artery among subjects with right moderate carotid plaque when compared to those without.

Bilateral carotid artery geometry using magnetic resonance angiography: a 10-year longitudinal single center study

Aging and atherosclerotic progression can lead to geometric changes in the carotid arteries. We conducted a longitudinal study to investigate geometric changes in the bilateral carotid arteries. We conducted a retrospective study of 177 subjects who underwent carotid contrast-enhanced magnetic resonance angiography (MRA) at our clinic at baseline and 10 years after the procedure. Semi-automated methods were used to segment the bilateral carotid arteries to obtain carotid artery geometric measurements. The mean age for the total population after 10 years was 70.7 ± 10.6 years (male, 40.1%). The mean time interval between baseline and after 10 years for all subjects was 130.2 ± 8.1 months. The bilateral bifurcation angle, the diameters for both common carotid arteries (CCAs), and areas of both CCAs significantly increased (p < 0.001) over a 10-year period. The maximum diameter and internal carotid artery area did not significantly change. The bifurcation angle of the right carotid artery was significantly increased compared to the left carotid artery. However, the diameter and area of the CCA of the left carotid artery was significantly increased compared to the right carotid artery. The bifurcation angle, diameter and area of both CCAs significantly increased over a decade. The change in the bifurcation angle over a 10-year period was predominant in the right carotid artery and the change of the area and diameter of the CCA was dominant in the left carotid artery.

Cerebrovascular Segmentation Model Based on Spatial Attention-Guided 3D Inception U-Net with Multi-Directional MIPs

The segmentation algorithm of cerebrovascular magnetic resonance angiography (MRA) images based on deep learning plays an essential role in medical study. Traditional segmentation algorithms face poor segmentation results and poor connectivity when the cerebrovascular vessels are thinner. An improved segmentation algorithm based on deep convolutional networks is proposed in this research. The proposed segmentation network combines the original 3D U-Net with the maximum intensity projection (MIP), which was transformed from the corresponding patch of a 3D MRA image. The MRA dataset provided by Jeonbuk National University Hospital was used to evaluate the experimental results in comparison with traditional 3D cerebrovascular segmentation methods and other state–of–the–art deep learning methods. The experimental results showed that our method achieved the best test performance among the compared methods in terms of the Dice score when Inception blocks and attention modules were placed in the proposed dual-path networks.

Evaluation of Plaque Vulnerability via Combination of Hemodynamic Analysis and Simultaneous Non-Contrast Angiography and Intraplaque Hemorrhage (SNAP) Sequence for Carotid Intraplaque Hemorrhage

The purpose of this study was to assess the vulnerability of plaque using a combination of simultaneous non-contrast angiography, intraplaque hemorrhage (SNAP) sequence, and local hemodynamic analysis in an intraplaque hemorrhage (IPH), and to evaluate the association between morphological and hemodynamic factors and IPH by comparing the IPH (presence of IPH) and non-IPH (plaque with absence of IPH) groups. In total, 27 IPH patients and 27 non-IPH patients were involved in this study, and baseline characteristics were collected. For morphological factors, diameters, and areas of the internal carotid artery (ICA), external carotid artery, and common carotid artery were measured, and bifurcation angle (α) and ICA angle (β) were also measured for comparison between the IPH group and non-IPH group. For hemodynamic factors, time-averaged wall shear stress (WSS), minimum WSS, maximum WSS, and oscillatory shear index were calculated using computational fluid dynamics (CFD) simulations. For the qualitative analysis, cross-sectional images with analyzed WSS and SNAP sequences were combined to precisely assess local hemodynamics. Bifurcation angle (α) was significantly different between the IPH and non-IPH groups (39.47 degrees vs. 47.60 degrees, p = 0.041). Significantly higher time-averaged WSS, minimum WSS, and maximum WSS were observed in the IPH group compared to the non-IPH group. In the IPH group, when using the combined analysis with SNAP sequences and WSS, the WSS of the region with IPH was significantly higher than the region without IPH (2.32 vs. 1.21 Pa, p = 0.005). A smaller bifurcation angle (α) and higher time-averaged WSS, minimum WSS, and maximum WSS were associated with IPH. The combined analysis of SNAP sequences and WSS might help to evaluate the risk of carotid IPH.

Influence of cardiovascular risk-factors on morphological changes of cerebral arteries in healthy adults across the life span

Cerebral artery morphological alterations have been associated with several cerebrovascular and neurological diseases, whereas these structures are known to be highly variable among healthy individuals. To date, the knowledge about the influence of cardiovascular risk factors on the morphology of cerebral arteries is rather limited. The aim of this work was to investigate the impact of cardiovascular risk factors on the regional cerebroarterial radius and density. Time-of-Flight magnetic resonance angiography from 1722 healthy adults (21-82 years) were used to extract region-specific measurements describing the main cerebral artery morphology. Multivariate statistical analysis was conducted to quantify the impact of cardiovascular risk factors, including clinical and life behavioural factors, on each region-specific artery measurement. Increased age, blood pressure, and markers of obesity were significantly associated with decreased artery radius and density in most regions, with aging having the greatest impact. Additionally, females showed significantly higher artery density while males showed higher artery radius. Smoking and alcohol consumption did not show any significant association with the artery morphology. The results of this study improve the understanding of the impact of aging, clinical factors, and life behavioural factors on cerebrovascular morphology and can help to identify potential risk factors for cerebrovascular and neurological diseases.

Carotid angle in young stroke

PURPOSE

To investigate whether the carotid bifurcation angle as assessed by computed tomographic angiography (CTA) is associated with anterior circulation ischemic stroke (ACIS) in young patients.

MATERIAL AND METHODS

Thirty patients (mean age 41.5 ± 6 years) with known acute ACIS (group 1) were compared to 30 control patients (mean age/ 41.2 ± 6 years) (group 2) with similar demographic variables in this retrospective study. Geometrical characteristics of bilateral carotid bifurcation were obtained by CTA. The ICA bifurcation (ICAB) angle, the carotid central bifurcation (CCB), and the carotid bifurcation wall (CBW) angle among the ICA, CCA, and ECA were measured. Carotid artery angle measurements were compared between group 1 and group 2. The comparison of pathological (ACIS) and non-pathological (non-ACIS) carotid sides in group 1 was performed as well.

RESULTS

All the measured angles (AMA) of group 1 were higher than group 2 (p˂0.05). In patients with left-sided ACIS, AMA on the left side were higher than the right side (p˂0.05), this was more prominent in males (p˂0.05). All angles measured were found to be higher in ipsilateral ACIS (p˂0.05). The left CCB angle values had a significant effect on ischemic stroke (p˂0.05). Male patients had more left-sided ACIS (p˂0.05). Plaque development in ICA was found statistically significant in group 1 compared to group 2 (p˂0.05).

CONCLUSION

Carotid artery geometry may play an important role in the development of ischemic events in young patients, especially in men and, also in patients with left-sided stroke. The left CCB angle had a significant effect on ACIS.

V Flow technology in measurement of wall shear stress of common carotid arteries in healthy adults: Feasibility and normal values

OBJECTIVE

To evaluate the feasibility of vector flow imaging technique (V Flow) in measurement of wall shear stress (WSS) of common carotid arteries (CCA) in healthy adults and to provide the normal WSS values assessed by V Flow.

METHODS & MATERIALS

This prospective study was approved by the Ethics Committee of our University. Eighty healthy adult volunteers were included (mean age 43.3 y, 47 females, 33 males). The volunteers were classified into three groups according to their age: group I (age 20 - 39 y), group II (age 40 - 59 y) and group III (age 60 - 80 y). Mindray Resona 8 ultrasound machine and a linear array transducer (3-9 MHz) was used, equipped with the updated V Flow function. Common carotid arteries of both sides were evaluated in three segments (initial segment, middle segment and near bifurcation segment). The WSS values of CCA were measured by two independent radiologists. The intraclass correlation coefficient (ICC) of observer reliability in WSS measurement was calculated. Inter-observer reproducibility was also evaluated with the 95% Bland-Altman limits of agreement (LOA).

RESULTS

V Flow measurements were performed successfully in 79 volunteers (98.8 %, 79/80). The mean value of WSS in right CCA was (0.66±0.24) Pa, in left CCA was (0.66±0.18) Pa (P > 0.05). Mean WSS value had a moderately negative correlation with age group (P < 0.05). The mean WSS value of group I(mean±SD, 0.75±0.25 Pa) is larger than group II (mean±SD, 0.62±0.13 Pa) and group III (mean±SD, 0.49±0.11 Pa) (P < 0.05). The ICC of observer reliability of group I, II and III was 0.96 (95% confidence interval (95% CI) 0.92-0.98), 0.94 (95% CI 0.88-0.97), 0.93 (95% CI 0.76-0.98) respectively. The Bland-Altman plots showed that the 95% LOA were -0.17-0.12 (Pa) for group I, -0.09-0.13 (Pa) for group II and -0.08-0.10 (Pa) for group III.

CONCLUSION

V Flow measurement is a simple, rapid and feasible imaging method for the WSS assessment of CCA in healthy volunteers, which will probably be an important tool for assessing CCA function.

Carotid Disease and Ageing: A Literature Review on the Pathogenesis of Vascular Senescence in Older Subjects

Aging is a natural process that affects all systems of the human organism, leading to its inability to adapt to environmental changes. Advancing age has been correlated with various pathological conditions, especially cardiovascular and cerebrovascular diseases. Carotid artery (CA) is mainly affected by age-induced functional and morphological alterations causing atheromatous disease. The evolvement of biomedical sciences has allowed the elucidation of many aspects of this condition. Symptomatic carotid disease (CD) derives from critical luminar stenosis or eruption of an atheromatous plaque due to structural modifications of the vessels, such as carotid intima-media thickening. At a histologic level, the aforementioned changes are mediated by elastin fragmentation, collagen deposition, immune cell infiltration, and accumulation of cytokines and vasoconstrictors. Underlying mechanisms include chronic inflammation and oxidative stress, dysregulation of cellular homeostatic systems, and senescence. Thus, there is an imbalance in components of the vessel wall, which fails to counteract exterior stress stimuli. Consequently, arterial relaxation is impaired and atherosclerotic lesions progress. This is a review of current evidence regarding the relationship of aging with vascular senescence and CD. A deeper understanding of these mechanisms can contribute to the production of efficient prevention methods and targeted therapeutic strategies.

Ultrasonography of a Helical Left Common Carotid Artery

Case Presentation

An 83-year-old woman was admitted to the intensive care unit for septic shock at which point an internal jugular central venous line was placed. The patient’s common carotid artery was visualized in an atypical location, lateral to the internal jugular vein. Further inspection revealed the common carotid artery travelling in a rotational trajectory around the internal jugular vein.

Discussion

For at least two decades, point-of-care ultrasound has become the standard of care for placing central venous lines. This surprising anatomical orientation is rare and cautions physicians to fully explore a patient’s anatomy prior to placing central lines.

The Chalice Sign : Characteristic Morphology of the Cervical Carotid Bifurcation in Patients with Loeys-Dietz Syndrome

BACKGROUND AND PURPOSE

Loeys-Dietz syndrome (LDS) is a connective tissue disorder characterized by arterial aneurysms and dissections. This study sought to assess and describe the arterial changes of the cervical arterial vasculature of such patients, with an emphasis on the carotid bifurcation.

MATERIAL AND METHODS

A retrospective review of patients with a known diagnosis of LDS was carried out. The maximum diameters of the external carotid artery (ECA) and internal carotid artery (ICA) origins, common carotid artery (CCA) terminus, maximum transverse and craniocaudal dimensions of the carotid bulb, and bifurcation angle were measured. The presence of a chalice sign was defined as a carotid bifurcation angle of ≥80°. A semi-quantified analysis of vertebral artery tortuosity was completed as well. All measurements were compared to a cohort of age-matched controls.

RESULTS

A total of 21 patients with LDS were included. Compared to normal controls, the presence of a chalice sign had 61.9% sensitivity and 100.0% specificity for LDS if present bilaterally; the sensitivity and specificity of a unilateral chalice sign were 66.7% and 82.3%, respectively. Patients with LDS also had significantly higher rates of a bilateral chalice sign compared to patients with vascular Ehlers-Danlos syndrome (vEDS) (61.9% versus 0%, P <0.0001) and patients with Marfan syndrome (61.9% versus 14.3%, P = 0.001).

CONCLUSION

Patients with LDS have characteristic findings of the cervical arterial vasculature that enables them to be distinguished from normal controls as well as patients with connective tissue diseases, such as Marfan syndrome and vEDS; most notably including marked widening of the carotid bifurcation angle in what is proposed to be named the chalice sign.

Quantitative phase contrast MRI of penetrating arteries in centrum semiovale at 7T

Pathological changes of penetrating arteries (PA) within the centrum semiovale is an important contributing factor of cerebral small vessel disease (SVD). However, quantitative characterization of the PAs remains challenging due to their sub-voxel sizes. Here, we proposed a Model-based Analysis of Complex Difference images (MACD) of phase contrast MRI capable of measuring the mean velocities (v_mean), diameters (D), and volume flow rates (VFR) of PAs without contamination from neighboring static tissues at 7 T. Simulation, phantom and in vivo studies were performed to evaluate the reproducibility and errors of the proposed method. For comparison, a Model-based Analysis of Phase difference images (MAP) was also carried out in the simulation. The proposed MACD analysis approach was applied in vivo to study the age dependence of PA properties in healthy subjects between 21 and 55 years old. Simulation showed that our proposed MACD approach yielded smaller errors than MAP, with errors increasing at lower velocities and diameters for both methods. In the phantom study, errors of the MACD-derived v_mean, D, and VFR were ≤20% of their true values when v_mean≥1cm/s and similar at different spatial resolutions. On the other hand, errors of the uncorrected apparent velocities were 24-60% and depended strongly on voxel size. The MACD errors linearly increased with the angle (α) between the vessel and slice normal direction at α ≤ 2° but remained almost constant at larger α. Results of the in vivo studies showed that the coefficients of repeatability for v_mean, D, and VFR for PAs with α = 0° were 0.67 cm/s, 0.060 mm, and 0.067 mm³/s, respectively. No significant age dependence was found for the number, v_mean, D, and VFR of PAs. The mean v_mean, D, and VFR over all PAs with α = 0° were 1.79 ± 0.62 cm/s, 0.17 ± 0.05 mm, and 0.36 ± 0.18 mm³/s, respectively. Quantitative measurements of PAs with the MACD method may serve as a useful tool for illuminating the vascular pathology in cerebral SVD.

Longitudinal study of carotid artery bifurcation geometry using magnetic resonance angiography

BACKGROUND AND PURPOSE

Carotid artery geometry has been suggested as a risk factor for atherosclerotic carotid disease. Although normal aging and disease development can both lead to geometric changes in the arteries, the exact nature of this phenomenon remains elusive. The aim of our study was to investigate carotid artery geometric changes in a longitudinal study.

MATERIAL AND METHODS

We conducted a retrospective study of 114 subjects who underwent carotid contrast-enhanced magnetic resonance angiography at our clinic at baseline (2005 to 2007) and after 10 years. The right (Rev#2-1) carotid arteries were segmented using semi-automated methods to obtain various measurements of carotid artery geometry. For each patient, these parameters were assessed at both time points, including bifurcation angle, internal carotid artery angle, vessel diameter, and circumference.

RESULTS

The median age for the total patient population (n = 114) at baseline was 59.06 ± 10.40 years. Mean time interval between baseline magnetic resonance angiography and magnetic resonance angiography after 10 years of these patients was 129.18 ± 7.77 months. For the whole group, there was a significant increase in the bifurcation angle (p < 0.05) over a 10-year period. A significant increase was also noted in the diameter and circumference of the common carotid artery (p < 0.05). However, the other vessel diameters and circumferences (bulb carotid, internal carotid) as well as the internal carotid angle did not significantly change (p ≥ 0.05).

CONCLUSION

The diameter and circumference of the common carotid artery and bifurcation angle significantly increased over a decade of life.

Longitudinal study of carotid artery bifurcation geometry using magnetic resonance angiography

OBJECTIVES

Geometry of carotid artery has been known as a risk factor for atherosclerotic carotid disease. Though aging and disease progression can both attribute to geometric changes in the arteries, the exact nature of this phenomenon remains elusive. The aim of our study was to investigate carotid artery geometric changes in a longitudinal study.

METHODS

We conducted a retrospective study of 114 subjects who underwent carotid contrast-enhanced magnetic resonance angiography at our clinic at baseline (2005 to 2007) and after 10 years. The right carotid arteries were segmented using semi-automated methods to obtain various measurements of carotid artery geometry. For each patient, these parameters were assessed at both time points, including bifurcation angle, internal carotid artery angle, vessel diameter, and circumference.

RESULTS

The median age for the total patient population ( n = 114) at baseline was 59.06 ± 10.40 years. Mean time interval between baseline magnetic resonance angiography and magnetic resonance angiography after 10 years of these patients was 129.18 ± 7.77 months. For the whole group, there was a significant increase in the bifurcation angle ( p < 0.05) over a 10-year period. A significant increase was also noted in the diameter and circumference of the common carotid artery ( p < 0.05). However, the other vessel diameters and circumferences (bulb carotid, internal carotid) as well as the internal carotid angle did not significantly change ( p ≥ 0.05).

CONCLUSIONS

The diameter and circumference of the common carotid artery and bifurcation angle significantly increased over a decade of life.