Accuracy of Transcranial Doppler Ultrasound Compared with Magnetic Resonance Angiography in the Diagnosis of Intracranial Artery Stenosis

Identification of middle cerebral artery stenosis in transcranial Doppler using a modified VGG-16

Objectives

The diagnosis of intracranial atherosclerotic stenosis (ICAS) is of great significance for the prevention of stroke. Deep learning (DL)-based artificial intelligence techniques may aid in the diagnosis. The study aimed to identify ICAS in the middle cerebral artery (MCA) based on a modified DL model.

Methods

This retrospective study included two datasets. Dataset1 consisted of 3,068 transcranial Doppler (TCD) images of the MCA from 1,729 patients, which were assessed as normal or stenosis by three physicians with varying levels of experience, in conjunction with other medical imaging data. The data were used to improve and train the VGG16 models. Dataset2 consisted of TCD images of 90 people who underwent physical examination, which were used to verify the robustness of the model and compare the consistency between the model and human physicians.

Results

The accuracy, precision, specificity, sensitivity, and area under curve (AUC) of the best model VGG16 + Squeeze-and-Excitation (SE) + skip connection (SC) on dataset1 reached 85.67 ± 0.43(%),87.23 ± 1.17(%),87.73 ± 1.47(%),83.60 ± 1.60(%), and 0.857 ± 0.004, while those of dataset2 were 93.70 ± 2.80(%),62.65 ± 11.27(%),93.00 ± 3.11(%),100.00 ± 0.00(%), and 0.965 ± 0.016. The kappa coefficient showed that it reached the recognition level of senior doctors.

Conclusion

The improved DL model has a good diagnostic effect for MCV stenosis in TCD images and is expected to help in ICAS screening.

The evaluation value of intracranial magnetic resonance angiography combined with carotid ultrasound in cerebral infarction

Objective

To explore the evaluation value of intracranial magnetic resonance angiography (MRA) combined with carotid ultrasound (CU) in patients with cerebral infarction (CI).

Methods

A retrospective analysis was conducted on 122 patients with CI who underwent intracranial MRA combined with CU examination in Shengzhou People's Hospital from January 2021 to October 2022. Vascular stenosis rate and CU parameters of patients with different degrees of nerve damage (ND) and size of CI lesion were analyzed.

Results

The rate of vascular stenosis and ultrasound parameters significantly varied between patients with different degrees of ND and different sizes of CI lesion. Spearman test showed a significant positive correlation between vascular stenosis, pulsatile index (PI), and resistance index (RI) with the degree of ND and the size of CI lesions in patients. There was a significant negative correlation between peak systolic velocity (PSV) and end-diastolic velocity (EDV) and the degree of ND and the size of CI lesions (P<0.05).

Conclusions

Intracranial MRA combined with CU can clarify the vascular stenosis and hemodynamic characteristics of patients with CI, and the combined approach closely correlates with the characteristics of CI, which can be used for disease assessment.

Effect of microbubbles on transcranial doppler ultrasound-assisted intracranial recombinant tissue-type plasminogen activator thrombolysis

OBJECTIVES

The aim of this study was to evaluate the effect of microbubbles on the efficacy of transcranial doppler (TCD) ultrasound-assisted thrombolytic therapy of recombinant tissue-type plasminogen activator (rt-PA).

METHODS

Male New Zealand white rabbits (n = 36) were randomly divided into an rt-PA group (n = 18) and an rt-PA plus microbubble group (n = 18). After the cerebral infarction model was constructed with autologous blood clots, rt-PA and rt-PA plus microbubble intervention were performed, respectively. The hemodynamic changes and infarct size of the two groups were recorded. In addition, the ELISA method was used to detect the level of nitric oxide (NO), superoxide dismutase (SOD), and malondialdehyde (MDA) in the brain tissue of the two-group graph model and high-sensitivity C-reactive protein (hs-CRP) in the serum.

RESULTS

In the rt-PA group, the recanalization rate was 38.9% and the average infarct size was 11.8%. In the rt-PA plus microbubble group, the recanalization rate was 66.7% and the average infarct size was 8.2%. In addition, the average values for NO, SOD, MDA, and hs-CRP were 16.48 ± 5.39 μmol/L, 730.2 ± 9.86 U/mg, 0.92 ± 0.43 nmol/mg, and 8.56 ± 1.64 mg/L in the rt-PA group, respectively, and the average values were 9.18 ± 3.37 μmol/L, 426.2 ± 6.39 U/mg, 0.73 ± 0.44 nmol/mg, and 5.23 ± 0.94 mg/L in the rt-PA plus microbubble group, respectively.

CONCLUSIONS

The addition of microbubbles enhanced the effects of TCD-assisted rrt-PA thrombolysis.

Application of transcranial Doppler in cerebrovascular diseases

Transcranial Doppler (TCD) is a rapid and non-invasive diagnostic technique that can provide real-time measurements of the relative changes in cerebral blood velocity (CBV). Therefore, TCD is a useful tool in the diagnosis and treatment of clinical cerebrovascular diseases (CVDs). In this review, the basic principles of TCD and its application in CVD were outlined. Specifically, TCD could be applied to evaluate occlusive CVD, assess collateral circulation in patients with ischemic stroke, and monitor cerebral vascular occlusion before and after thrombolysis as well as cerebral vasospasm (VSP) and microembolization signals after aneurysmal subarachnoid hemorrhage (SAH). Moreover, TCD could predict short-term stroke and transient cerebral ischemia in patients with anterior circulation occlusion treated with endovascular therapy and in patients with anterior circulation vascular occlusion. Additionally, TCD not only could monitor blood velocity signals during carotid endarterectomy (CEA) or carotid artery stenting (CAS) but also allowed earlier intervention through early recognition of sickle cell disease (SCD). Presently, TCD is a useful prognostic tool to guide the treatment of CVD. On the one hand, TCD is more commonly applied in clinical research, and on the other hand, TCD has an increasing role in the management of patients. Collectively, we review the principles and clinical application of TCD and propose some new research applications for TCD.

Transcranial Doppler Ultrasonography as a Diagnostic Tool for Cerebrovascular Disorders

Imaging techniques including transcranial Doppler (TCD), magnetic resonance imaging (MRI), computed tomography (CT), and cerebral angiography are available for cerebrovascular disease diagnosis. TCD is a less expensive, non-invasive, and practically simpler approach to diagnosing cerebrovascular disorders than the others. TCD is a commonly available and inexpensive diagnostic tool. However, owing to its large operator dependency, it has a narrow application area. Cerebrovascular disease indicates a group of disorders that alter the flow of blood in the brain. The brain’s functions can be temporarily or permanently impaired as a result of this change in blood flow. Timely diagnosis and treatment can restore the brain-impaired functions, resulting in a much-improved prognosis for the patients. This review summarizes the basic principles underlying the TCD imaging technique and its utility as a diagnostic tool for cerebrovascular disease.

TCD hemodynamics findings in the subacute phase of anterior circulation stroke patients treated with mechanical thrombectomy

Despite mechanical thrombectomy, the prognosis for many patients with anterior circulation ischemic stroke (ACIS) remains poor. This retrospective study reports consecutive mechanical thrombectomy procedures for ACIS at our hospital over 4 years. Hemodynamics were explored using transcranial Doppler ultrasound. The functional outcome was assessed using the modified Rankin scale. A total of 121 eligible cases were included: 61 (50.4%) exhibited good outcomes (modified Rankin scale score ≤2) by day 90. The logistic regression analysis showed that ipsilateral middle cerebral artery (iMCA) systolic blood flow (SBF) (OR = 0.983, 95% CI: 0.969–0.997, P = 0.014), preoperative National Institutes of Health Stroke Scale (NIHSS)score (OR = 1.160, 95% CI: 1.067–1.261, P < 0.001), intracranial hemorrhage after therapy (OR = 19.514, 95% CI: 4.364–87.265, P < 0.001), and Alberta Stroke Program Early Computed Tomography Score (OR = 0.639, 95% CI: 0.416–0.981, P = 0.040) were independently associated with prognosis. The iMCA SBF and preoperative NIHSS score were significantly predictive of a good outcome in the receiver operating characteristic analysis. In conclusion, elevated iMCA SBF might be a prognostic indicator of a good 90-day outcome following endovascular treatment in ACIS patients treated with mechanical thrombectomy, but large prospective studies are mandatory to validate the findings of our study.

Cardiovascular and cerebrovascular risk markers in Parkinson's disease: Results from a case-control study

BACKGROUND

The relationship between Parkinson's disease (PD) and cardiovascular and cerebrovascular disease is not yet well established. Recent data suggest an increased risk of myocardial infarction and stroke in PD patients. Therefore, we designed a study to assess surrogate markers of cardiovascular and cerebrovascular risk in PD.

METHODS

We conducted a case-control study comparing PD patients recruited from a Movement Disorders Unit with controls randomly invited from a primary healthcare center. All participants underwent a detailed clinical evaluation, including medical history, physical assessment, carotid ultrasound, blood and urine analysis, and 24-h ambulatory blood pressure monitoring. The primary outcome was the carotid intima-media thickness (CIMT).

RESULTS

We included 102 participants in each study arm. No significant difference was found in the CIMT among groups (MD: 0.01, 95% CI: -0.02, 0.04). Carotid plaques were more frequent in PD patients (OR: 1.90, 95% CI: 1.02, 3.55), although the lipid profile was more favorable in this group (LDL MD: -18.75; 95% CI: -10.69, -26.81). Nocturnal systolic blood pressure was significantly higher in PD patients (MD: 4.37, 95% CI: 0.27, 8.47) and more than half of the PD patients were non-dippers or reverse dippers (OR: 1.83, 95% CI: 1.04, 3.20).

CONCLUSION

We did not find a difference in CIMT between PD and controls. A higher frequency of carotid plaques and abnormal dipper profile supports the hypothesis that PD patients are not protected from cardiovascular and cerebrovascular disease.

Association Between Cumulative Exposure to Increased Low-Density Lipoprotein Cholesterol and the Prevalence of Asymptomatic Intracranial Atherosclerotic Stenosis

Background and Purpose: Intracranial atherosclerosis has gained increasing attention due to the high risk of recurrent clinical or subclinical ischemic events, while the relationship between low-density lipoprotein cholesterol (LDL-C) measured at a single time point and intracranial atherosclerotic stenosis (ICAS) is inconsistent. This study aims to assess the association between cumulative exposure to increased LDL-C and the prevalence of asymptomatic ICAS.

Methods: The Asymptomatic Polyvascular Abnormalities Community study was investigated on the epidemiology of asymptomatic polyvascular abnormalities in Chinese adults. In this study, we included 4,523 participants with LDL-C measured at 3 examinations in 2006, 2008, and 2010. Cumulative exposure to increased LDL-C was calculated as following: LDL-C burden_2006−2008 = [(LDL-C₂₀₀₆-1.8) + (LDL-C₂₀₀₈-1.8)]/2 ^* time_2006−2008; LDL-C burden = LDL-C burden_2006−2008 + LDL-C burden_2008−2010. Transcranial doppler ultrasonography was performed in 2010 to detecting the ICAS.

Results: Of the 4,347 patients, 13.3% (580/4,347) were diagnosed with ICAS. In univariate analysis, the association between LDL-C burden and ICAS prevalence was significant, the odds ratios (95% confidence interval) from the lowest to the highest quartile were 1 (reference), 1.30 (0.99–1.70), 1.32 (1.01–1.73), and 2.14 (1.66–2.75), respectively (P < 0.05). After adjustment for potential confounding factors, the same result was reached.

Conclusions: Cumulative exposure to increased LDL-C is concentration-dependently associated with increased prevalence of asymptomatic ICAS, especially in those under the age of 65 y or free of hypertension, diabetes mellitus, and hyperlipidemia.