European Journal of Cardiovascular Medicine

Stroke is a leading cause of death and disability globally, and early diagnosis is crucial for effective treatment to reduce long-term effects. Carotid artery ultrasound, particularly color Doppler sonography, is widely used for diagnosing atheromatous disorders, including carotid stenosis, a major cause of ischemic stroke. Accurate diagnosis is essential for timely intervention, as prompt treatment can significantly lower stroke risk and its complications.

Various diagnostic methods exist for evaluating carotid artery pathology, with non-invasive tests being highly valuable. This study compares the effectiveness of extracranial carotid and vertebral artery Doppler with magnetic resonance angiography (MRA) in stroke patients. Color Doppler sonography has long been established as an accurate, non-invasive tool for assessing extracranial carotid atherosclerosis, surpassing traditional angiography due to its safety, accuracy, and patient comfort. Unlike digital subtraction angiography (DSA), which is invasive, costly, and carries the risk of contrast-related complications, ultrasound offers a more accessible alternative.^[1]

In symptomatic patients, such as those with hemispheric symptoms or TIA, carotid ultrasonography may be the only imaging technique used before carotid endarterectomy.^[2] The primary advantage of sonography lies in its ability to detect plaques at high risk for embolization, especially those with intra-plaque hemorrhage, a precursor to plaque rupture and ulceration.^[3] Additionally, Doppler ultrasound has expanded to assess other vascular conditions like aneurysms, dissections, and Takayasu’s arteritis.^[2,3]

Non-contrast MRA offers excellent sensitivity for high-grade stenosis and provides reproducible three-dimensional images of the carotid bifurcation, Circle of Willis, and vertebrobasilar system, without operator dependency.^[3] This makes it a valuable tool for preoperative evaluation, effectively replacing DSA in many cases.

Aims and Objectives

The aim of this study is to assess the status of the carotid and vertebral arteries in patients with ischemic stroke and Transient Ischemic Attack (TIA) using ultrasound Doppler and MRI imaging techniques. The primary objective is to evaluate the presence of stenosis, plaques, and other vascular abnormalities through these diagnostic tools. Additionally, the study seeks to correlate the morphological characteristics of the arteries as observed in ultrasound Doppler with those seen in Magnetic Resonance Angiography (MRA), thereby comparing the diagnostic accuracy and effectiveness of these two imaging methods in stroke and TIA patients.

Study Design

This prospective cross-sectional study was conducted between July 2023 and July 2024 at Dhanalakshmi Srinivasan Medical College and Hospital, Perambalur. The study involved patients who were admitted with a diagnosis of ischemic stroke or Transient Ischemic Attack (TIA).Participants were selected based on clinical diagnosis of stroke or TIA, and the data collected provided insights into the vascular pathology associated with these conditions.

Inclusion and Exclusion Criteria

The inclusion criteria for this study were patients who were clinically and radiologically confirmed to have ischemic stroke, as well as those clinically diagnosed with Transient Ischemic Attack (TIA). The exclusion criteria included patients with evidence of hemorrhagic stroke, stroke resulting from head injury, road traffic accidents, cardiac disease, or coagulopathy, as well as individuals with chronic infarcts. Additionally, patients under 18 years of age and those who were uncooperative were excluded from the study to ensure accurate diagnostic evaluation and patient cooperation during imaging procedures.

Sample Size Calculation

According to Jeyaraj et al, Prevalence of ischemic stroke – 73%

n ≥ [Z² _1-α/2 x p(1-p)] /d²

z = 1.96, p = 0.73, d = 0.10

n ≈ 76

The sample size is equal to 76.

Data Collection Procedure

Data collection for this study involved gathering both clinical and imaging data from each patient. The clinical history of the patient was recorded, including relevant details of their stroke or TIA presentation. Imaging data included measurements of carotid artery intima-media thickness, velocities, and direction of flow in both the carotid and vertebral arteries, as well as the site and percentage of any observed occlusions. Plaque morphology was assessed using both ultrasound and MRI, and MRI & TOF-MRA brain findings were documented.

Additionally, a lipid profile was obtained for each patient. Brain and neck imaging were performed using a PHILIPS ACHIEVA 1.5 TESLA MRI machine, while carotid and vertebral artery Doppler imaging was conducted with either the PHILIPS AFFINITI 50G or PHILIPS CLEAR VUE 650 systems, utilizing a linear probe for grey scale and color Doppler analysis. These combined imaging and clinical data were used for thorough evaluation and analysis of the vascular pathology associated with stroke and TIA.

Statistical Analysis

The data collected in this study were entered into Microsoft Excel and analyzed using SPSS version 22. Continuous variables were expressed as mean values with standard deviation, while categorical variables were presented as proportions. To compare proportions between different groups, the chi-square test or Fisher's exact test was applied, depending on the data distribution. These statistical methods enabled a detailed evaluation of the relationships and differences in vascular characteristics between patients with ischemic stroke and TIA.

Table 1 shows the demographic profile of the study population, highlighting that most participants were aged 31–45 years, predominantly male, and sustained injuries mainly from falls from height.

Table 2 observes that Sanders Type II fractures were more common, and surgeries performed via the Sinus Tarsi approach occurred earlier than those using the Extensile Lateral approach.

Table 3 illustrates significant improvement in Böhler and Gissane angles post-operatively for both groups, with statistically meaningful differences between approaches.

Table 4 shows that operative duration and hospital stay were significantly shorter for the Sinus Tarsi approach, reflecting reduced invasiveness and faster recovery.

Table 5 presents early and late post-operative complications, showing no significant difference between approaches, though wound issues were slightly higher in the Extensile Lateral group.

Table 6 shows consistent improvement in functional outcomes across follow-up periods, with the Sinus Tarsi approach demonstrating superior AOFAS, Maryland, and VAS scores.

Table 7 observes that patients treated via the Sinus Tarsi approach achieved earlier full weight bearing and returned to work significantly faster compared to those treated with the Extensile Lateral approach.

Atherosclerotic disease of the extracranial carotid arteries, particularly within 2 cm of the carotid bifurcation, is a significant contributor to ischemic strokes, accounting for approximately 30–60% of stroke cases. This condition highlights the importance of accurate diagnostic tools, such as carotid Doppler ultrasound, for evaluating plaque characteristics and stenosis. Sonography's ability to evaluate plaque composition distinguishes it from other imaging techniques, offering vital prognostic information when deciding between medical and surgical interventions. Notably, the identification of high-risk plaques, such as those with intra-plaque hemorrhage, is critical in preventing adverse neurological events.^[1]

In the study by Fernandez et al., the age group of 60–69 years had the largest percentage of stroke patients (32%), followed by those aged 70–79 years (26%).^[4] Gender distribution in this study revealed that 72% of the stroke patients were male, in compare to 28% female patients, aligning with the male predilection observed in other studies.^[5] Similarly, the study by Iemolo et al. reported that only 2.5% of stroke victims were women, highlighting the higher stroke incidence in men compared to women.^[5]

Color Doppler ultrasound remains a cornerstone in the diagnosis of carotid artery stenosis, with several Doppler indices, such as peak systolic velocity (PSV) and end-diastolic velocity (EDV), playing a crucial role in assessing the degree of stenosis. Among these, the PSV ratio (ICA/CCA) is particularly valuable as it accounts for physiological and equipment variability, making it an effective marker for identifying significant stenosis.^[6] A PSV ratio >1.8 typically indicates stenosis of 60% or more, while a ratio of 3.7 signifies stenosis of over 80% in diameter. The North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the European Carotid Endarterectomy Trial (ECST) have demonstrated that symptomatic patients with 60-70% stenosis benefit significantly from surgical intervention compared to medical therapy.^[6] Moreover, a PSV ratio of 1.5 has been found to reliably indicate stenosis of 50% or more, reinforcing its diagnostic value.^[6]

Duplex ultrasound is also highly effective in diagnosing complete carotid occlusion by identifying the absence of arterial pulse, echogenic lumen, and subnormal artery size. In a study by Schulte-Altedorneburg et al., 64% of patients had steno-occlusive carotid lesions, which is consistent with the high prevalence of carotid plaque in stroke patients.^[7] In Fernandez et al.'s study, 78% of stroke patients had carotid artery plaques, with 23 patients (46%) exhibiting bilateral involvement, which highlights the widespread nature of atherosclerotic disease in stroke patients.^[8]

The relationship between stenosis severity and stroke type is well established. Von Jessen and Sillesen reported that only 17% of TIA patients had stenosis greater than 50%, while persistent central neurological symptoms (stroke) were observed in patients with more than 50% stenosis.^[9] This suggests that significant stenosis is more commonly associated with stroke, while milder stenosis may be implicated in TIA. In Fernandez et al.'s study, 12 patients with >60% stenosis experienced varying degrees of neurological deficits, including hemiplegia and hemiparesis.^[4] Additionally, Seth et al. demonstrated that patients with >40% stenosis predominantly had cortical infarcts, while subcortical infarcts were observed only in those with minimal stenosis, underscoring the link between severe stenosis and infarct location.^[10]

Regarding the comparison of MRA and Doppler ultrasound, studies like Erickson et al. (1989) have shown that MRA offers superior discriminatory power in detecting 70-99% stenosis, especially in detecting occlusions.^[11] However, MRA may be less reliable in assessing mild to moderate stenosis (50-70%), often overestimating the degree of stenosis and leading to false positives, as noted by Serfaty et al.^[12] These findings suggest that while MRA is a useful tool, it should be used in conjunction with other diagnostic modalities like Doppler ultrasound for comprehensive assessment.

Furthermore, the composition of the atherosclerotic plaque plays a critical role in stroke risk, with soft or non-homogeneous plaques being more likely to cause neurological events. Research by Aburahma et al and Wulu et al has confirmed the stronger correlation between plaque characteristics (such as vulnerability to rupture) and the occurrence of symptoms, rather than the degree of stenosis alone.^[13] This highlights the importance of evaluating plaque morphology in addition to stenosis to better predict stroke risk.

The use of carotid Doppler ultrasound and MRA provides valuable insights into the degree of stenosis, plaque morphology, and occlusion, all of which are crucial for stroke prevention and management. The study findings align with existing literature, reinforcing the need for early detection and appropriate intervention based on both stenosis severity and plaque characteristics.

Limitations

This study was conducted with a relatively small sample size, which may limit the generalizability of the findings. Additionally, data from multiple observers were used, which introduces the potential for inter-observer variability. As a result, it was not possible to completely eliminate the possibility of observer bias, which could affect the consistency and accuracy of the results.

In this study, individuals with ischemic stroke and transient ischemic attack (TIA) were found to have a high prevalence of carotid artery disease, as evidenced by increased intima-media thickness, the presence of plaques, and severe stenosis in the internal carotid artery. Moreover, patients with significant stenosis were found to have larger infarcts, highlighting the severity of the condition. These findings emphasize the importance of carotid Doppler analysis in stroke prevention. In the South Indian population, early detection of carotid plaques plays a critical role in guiding medical and surgical interventions for patients suffering with stroke and TIA.

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