scholarly journals Ultrasound signs of atherosclerotic plaques destabilization in carotid arteries

2019 ◽  
pp. 70-75
Author(s):  
D. E. Zaitsev ◽  
A. S. Lepekhina ◽  
G. E. Trufanov
Keyword(s):  
Carotid Arteries ◽  
Atherosclerotic Lesions ◽  
Asymptomatic Patients ◽  
Single Use ◽  
The Mean ◽  
Clinical Questions ◽  
Ischemic Attack ◽  
The Moment ◽  
Vascular Center

Aim. To assess the ultrasonography role for diagnosis of atherosclerotic lesions of the extracranial carotid arteries.Material and methods. The study was conducted on the basis of the St. Petersburg Mariinsky Hospital. A total of 855 patients who were admitted to the regional vascular center due to ischemic stroke or transient ischemic attack were examined. The mean age of the patients was 68 years (min 18, max 107). All patients underwent ultrasound of the carotid arteries.Results. In 570 (66,6%) patients with neurological symptoms (according to clinical and neurological examination), hemodynamically insignificant carotid artery lumen stenosis up to 70-75% was revealed. Ultrasound imaging in all patients revealed signs of atherosclerotic plaque (ASP) instability in various combinations, except for hemorrhage. It was not possible to clearly visualize the finished hemorrhage in the ASP structure.Conclusion. Despite the high informative value of ultrasound, it is not possible to answer all clinical questions with its single use. At the moment, there is no classification of instability signs, reflecting the ASP embolism risk. It needs for paternal change the management of asymptomatic patients. More detailed study of ASP destabilization using various visualization methods is necessary.

scholarly journals INDICATIONS TO SURGICAL TREATMENT OF ATHEROSCLEROTIC IMPACT OF THE CAROTID ARTERIES

2020 ◽  
pp. 76-80
Author(s):  
I. S. Puliayeva
Keyword(s):  
Ischemic Stroke ◽  
Surgical Treatment ◽  
Carotid Artery ◽  
Carotid Arteries ◽  
Recurrent Stroke ◽  
Comprehensive Treatment ◽  
Hemorrhagic Complication ◽  
Atherosclerotic Lesions ◽  
Asymptomatic Patients ◽  
Ica Stenosis

Summary. Goal. To analyze the indications for surgical treatment of symptomatic and asymptomatic stenosis of the internal carotid artery. Materials and methods. The well-known tactics of performing carotid endarterectomy in symptomatic and asymptomatic patients still need to be divided into groups with symptomatic and asymptomatic ICA stenosis, depending on the clinical course of the disease and the risk of developing stroke. Of the 140 patients enrolled in the study, 60 patients formed patients with symptomatic ICA lesions, namely: a) 50 patients with symptomatic ICA stenosis; b) 10 patients with visual impairment and ICA stenosis. Of 80 asymptomatic patients with verified atherosclerotic lesions of the carotid arteries without manifestations of acute ischemic cerebral circulation during the last 6 months, of which. Discussion and results. Patients with symptomatic ICA lesions are the most at-risk group for the development of recurrent stroke, they require comprehensive treatment depending on the size of the lesion and the risk of hemorrhagic complication. Conclusions. Patients with multifocal atherosclerosis should be screened for carotid artery screening to reduce the risk of ischemic stroke in the postoperative period. Patients with ischemic stroke should perform an MRI to confirm the focus of the first stage, followed by ultrasound examination of the carotid arteries. In the case of carotid lesions, patients undergo carotid CT scans to establish indications for surgical treatment.

scholarly journals Possibilities of Ultrasound Dopplerography in Detecting Instability of Atherosclerotic Plaque of Carotid Arteries

2019 ◽  
Vol 6 (3) ◽  
pp. 36-43
Author(s):  
D. E. Zaitsev ◽  
G. E. Trufanov
Keyword(s):  
Atherosclerotic Plaque ◽  
Carotid Arteries ◽  
Imaging Techniques ◽  
Detailed Examination ◽  
Atherosclerotic Plaques ◽  
Imaging Method ◽  
Plaque Instability ◽  
Atherosclerotic Lesions ◽  
Ischemic Attack ◽  
Design And Methods

Background. Studying the possibilities of ultrasound diagnosis of atherosclerotic lesions of the carotid arteries to determine the treatment tactics of patients with various types of atherosclerotic plaques.Objective. Assessment of the possibilities of ultrasonic triplex research in identifying signs of instability of atherosclerotic plaques of the carotid arteries.Design and methods. The study included 360 patients aged from 28 to 95 years old who were admitted to the St. Petersburg State Budgetary Health Institution “Mariinskaya Hospital” with diagnoses of transient ischemic attack and acute cerebrovascular accident. All patients underwent an ultrasound visualization of the brachiocephalic arteries. Results. Most patients had atherosclerotic plaques of the carotid arteries with a stenosis of up to 75 % and had signs of instability with varying degrees of severity (according to triplex ultrasound). However, it was not possible to reliably assess the presence of hemorrhage in the plaque using a single imaging method.Conclusion. The data obtained indicate the complexity and ambiguity of the studied question. Further detailed examination of the signs of atherosclerotic plaque instability is required using various diagnostic imaging techniques.

Three Dimensional Reconstruction of the Components of the Carotid Plaque From Standard CT Medical Images

2011 ◽  
Author(s):  
Dipankar Biswas ◽  
Francis Loth ◽  
Susan McCormick ◽  
Hisham Bassiouny
Keyword(s):  
Carotid Arteries ◽  
Three Dimensional ◽  
Plaque Burden ◽  
Asymptomatic Group ◽  
Symptomatic Group ◽  
Asymptomatic Patients ◽  
Dimensional Reconstruction ◽  
Manual Selection ◽  
The Mean ◽  
Human Carotid

The present study compares plaque and calcium volumes between sixteen diseased human carotid arteries. Half were from symptomatic patients, and half were from asymptomatic patients. In-house software was developed for the 3-D reconstruction of the plaque components from computerized tomography (CT) images. Results revealed higher mean total volume (TV) in the symptomatic group compared to the asymptomatic group. In contrast, the mean ratio of calcium volume (CV) to TV was lower for the symptomatic group compared to the asymptomatic group. This shows that symptomatic patients have a significantly greater plaque burden with minimal plaque calcification. The process of acquiring the data helped understand what tools/features are needed to conduct this work. One important feature of this software is the ability to create automated regions of interest (ROI) in addition to simple manual selection/modification of the ROIs in a GUI environment.

Features of Thrombi and Diagnostic Accuracy of Impedance Plethysmography in Symptomatic and Asymptomatic Deep Vein Thrombosis

1993 ◽  
Vol 70 (02) ◽  
pp. 266-269 ◽  
Author(s):  
Giancarlo Agnelli ◽  
Benilde Cosmi ◽  
Stefano Radicchia ◽  
Franca Veschi ◽  
Enrico Boschetti ◽  
...  
Keyword(s):  
Deep Vein Thrombosis ◽  
Diagnostic Accuracy ◽  
High Sensitivity ◽  
Impedance Plethysmography ◽  
Surveillance Programme ◽  
Vein Thrombosis ◽  
Asymptomatic Patients ◽  
High Prevalence ◽  
The Mean ◽  
Deep Vein

SummaryImpedance plethysmography (IPG) has high sensitivity and specificity in patients with symptomatic deep vein thrombosis (DVT) while it fails to detect asymptomatic DVT. The aim of this study was to determine whether the features of thrombi such as location, size and occlusiveness could explain the different accuracy of IPG in symptomatic and asymptomatic DVT patients. One-hundred and seventeen consecutive outpatients with a clinical suspicion of DVT and 246 consecutive patients undergoing hip surgery were admitted to the study. In symptomatic patients IPG was performed on the day of referral, followed by venography, while in asymptomatic patients IPG was performed as a surveillance programme, followed by bilateral venography.A venography proved DVT was observed in 37% of the symptomatic patients and 34% of the asymptomatic limbs. A significantly higher proportion of proximal DVTs was found in symptomatic patients than in asymptomatic patients (78% vs 46%; p = 0.001). The mean Marder score, taken as an index of thrombus size, was significantly higher in symptomatic patients than in asymptomatic patients (19.0 vs 9.6; p = 0.0001). A significantly higher proportion of occlusive DVTs was observed in symptomatic than in asymptomatic patients (69% vs 36%; p = 0.001).We conclude that the unsatisfactory diagnostic accuracy of IPG in asymptomatic DVT is due to the high prevalence of distal, small and non occlusive thrombi. Such thrombi are unlikely to cause a critical obstruction of the venous outflow and therefore to produce a positive IPG.

Improving management as a way to increase labour productivity

Upravlenie ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 24-30
Author(s):  
A. O. Ivanov
Keyword(s):  
Productivity Growth ◽  
Labour Productivity ◽  
Production Costs ◽  
Managerial Practices ◽  
Industrial Enterprises ◽  
Labour Productivity Growth ◽  
Period 2 ◽  
Main Factors ◽  
The Moment

The article gives an overview, performs analysis and classification of successful managerial practices applied at Russian industrial enterprises in the framework of the national project “Labour productivity and employment support”. The paper emphasizes the main factors of labour productivity growth as follows: investment policy, growth of human capital, and efficient use of managerial capital of enterprise. In order to determine the need of enterprises to increase labour productivity, the author proposes four universal criteria that signal the existing inefficiency even before the loss of competitiveness: 1) the dynamics of labour productivity in the company is not positive during a given period; 2) the company is behind competitors by labour productivity indicator; 3) the company is behind competitors by labour productivity growth rates indicator for a certain period; 4) unit production costs rise. These criteria allow you to take into account the situation both within the enterprise and in comparison with other enterprises. Each criteria can be considered separately or in combination with the others, applied to enterprises of different industries, specialization, and scale. Criteria indicate the direction of development in which the company is experiencing difficulties at the moment, or may experience them in the future.

scholarly journals Blood eosinophils and serum eosinophil cationic protein in patients with acute and chronic urticaria

1996 ◽  
Vol 5 (2) ◽  
pp. 113-115 ◽  
Author(s):  
G. Di Lorenzo ◽  
P. Mansueto ◽  
M. Melluso ◽  
G. Candore ◽  
D. Cigna ◽  
...  
Keyword(s):  
Chronic Urticaria ◽  
Eosinophil Cationic Protein ◽  
Chronic Idiopathic Urticaria ◽  
Blood Eosinophil ◽  
Cationic Protein ◽  
Acute Urticaria ◽  
Asymptomatic Patients ◽  
The Moment ◽  
Blood Eosinophils ◽  
Eosinophil Counts

We have analysed the relationship of blood eosinophil count and serum eosinophil cationic protein (ECP) levels in patients with acute and chronic idiopathic urticaria. The ECP levels and eosinophil counts were measured in the peripheral blood of 15 patients with acute urticaria, 25 with chronic idiopathic urticaria and 10 normal healthy subjects. Blood eosinophil counts and serum ECP levels increased in all patients with acute urticaria. Concerning patients affected by chronic urticaria, taking into account the recrudescence of the disease at the moment of taking the blood sample, only symptomatic patients showed increased eosinophil blood values whereas serum ECP levels were increased both in symptomatic and asymptomatic patients. Furthermore, serum ECP levels in chronic urticaria did not correlate with the peripheral eosinophil counts, as they did in acute urticaria. The results of the present study indicate that eosinophils may play a role in the inflammatory mechanisms in patients with acute and chronic urticaria showing a positive correlation between serum ECP levels and disease activity.

scholarly journals Carotid webs produce greater hemodynamic disturbances than atherosclerotic disease: a DSA time–density curve study

2021 ◽  
pp. neurintsurg-2021-017588
Author(s):  
Charlie C Park ◽  
Retta El Sayed ◽  
Benjamin B Risk ◽  
Diogo C Haussen ◽  
Raul G Nogueira ◽  
...  
Keyword(s):  
Logistic Regression ◽  
Carotid Artery ◽  
Carotid Arteries ◽  
Region Of Interest ◽  
Hemodynamic Parameters ◽  
Density Curve ◽  
Atherosclerotic Lesions ◽  
Clinically Significant ◽  
Flow Stasis ◽  
Time Density

BackgroundCarotid webs (CaWs) are associated with ischemic strokes in younger patients without degrees of stenosis that are traditionally considered clinically significant.ObjectiveTo compare the hemodynamic parameters in the internal carotid artery (ICA) bulbar segment in patients with CaW with those in patients with atherosclerotic lesions using time–density curve (TDC) analysis of digital subtraction angiography (DSA) images.MethodsWe retrospectively assessed DSA images of 47 carotid arteries in 41 adult patients who underwent ICA catheter angiography for evaluation after ischemic stroke. Hemodynamic parameters, including full width at half maximum (FWHM) and area under the time–density curve (AUC) as proxies for increased flow stasis, were calculated using TDC analyses of a region of interest (ROI) in the ICA bulb immediately rostral to the web/atherosclerotic plaque, relative to a standardized ROI in the ipsilateral distal common carotid artery (eg, relative FWHM (rFWHM)). Hemodynamic parameters were compared using non-parametric Kruskal-Wallis tests. Logistic regression was used to predict CaW versus mild/moderate atherosclerosis for each hemodynamic parameter, adjusting for degree of stenosis.ResultsMean age of patients was 56.0±13 years, with 22 (53.7%) women. 17 CaWs, 22 atherosclerotic plaques (15 mild/moderate and 7 severe), and eight normal carotid arteries were assessed. Significant between-group differences were present in the relative total AUC (p<0.001), relative AUC at wash out (p=0.031), and relative FWHM (p=0.001). Logistic regression to predict CaW versus mild/moderate atherosclerosis showed that rAUC total had the highest predictive value (pAUC=0.96, 95% CI 0.90 to 1.00), followed by rFWHM (0.87, 95% CI 0.74 to 1.00), and rAUC WO (0.74, 95% CI (0.57 to 0.91).ConclusionCaW results in larger local hemodynamic disruption, characterized by flow stasis, than mild/moderate carotid atherosclerotic lesions, suggesting that CaWs may produce larger regions of thrombogenic flow stasis.

scholarly journals Helium, [Fe/H] Abundances and the HR (Log TEFF, MBol) Diagram With Hipparcos Data of The Four Nearest Open Clusters: Hyades, Coma Berenices, The Pleiades and Praesepe

1998 ◽  
Vol 11 (1) ◽  
pp. 565-565
Author(s):  
G. Cayrel de Strobel ◽  
R. Cayrel ◽  
Y. Lebreton
Keyword(s):  
Main Sequence ◽  
Open Clusters ◽  
Main Sequence Stars ◽  
Spectroscopic Analyses ◽  
Solar Metallicity ◽  
Metal Abundances ◽  
The Mean ◽  
The Moment ◽  
The One ◽  
Best Fit

After having studied in great detail the observational HR diagram (log Teff, Mbol) composed by 40 main sequence stars of the Hyades (Perryman et al.,1997, A&A., in press), we have tried to apply the same method to the observational main sequences of the three next nearest open clusters: Coma Berenices, the Pleiades, and Praesepe. This method consists in comparing the observational main sequence of the clusters with a grid of theoretical ZAMSs. The stars composing the observational main sequences had to have reliable absolute bolometric magnitudes, coming all from individual Hipparcos parallaxes, precise bolometric corrections, effective temperatures and metal abundances from high resolution detailed spectroscopic analyses. If we assume, following the work by Fernandez et al. (1996, A&A,311,127), that the mixing-lenth parameter is solar, the position of a theoretical ZAMS, in the (log Teff, Mbol) plane, computed with given input physics, only depends on two free parameters: the He content Y by mass, and the metallicity Z by mass. If effective temperature and metallicity of the constituting stars of the 4 clusters are previously known by means of detailed analyses, one can deduce their helium abundances by means of an appropriate grid of theoretical ZAMS’s. The comparison between the empirical (log Teff, Mbol) main sequence of the Hyades and the computed ZAMS corresponding to the observed metallicity Z of the Hyades (Z= 0.0240 ± 0.0085) gives a He abundance for the Hyades, Y= 0.26 ± 0.02. Our interpretation, concerning the observational position of the main sequence of the three nearest clusters after the Hyades, is still under way and appears to be greatly more difficult than for the Hyades. For the moment we can say that: ‒ The 15 dwarfs analysed in detailed in Coma have a solar metallicity: [Fe/H] = -0.05 ± 0.06. However, their observational main sequence fit better with the Hyades ZAMS. ‒ The mean metallicity of 13 Pleiades dwarfs analysed in detail is solar. A metal deficient and He normal ZAMS would fit better. But, a warning for absorption in the Pleiades has to be recalled. ‒ The upper main sequence of Praesepe, (the more distant cluster: 180 pc) composed by 11 stars, analysed in detail, is the one which has the best fit with the Hyades ZAMS. The deduced ‘turnoff age’ of the cluster is slightly higher than that of the Hyades: 0.8 Gyr instead of 0.63 Gyr.

scholarly journals AVERAGING OF AN INCREASING NUMBER OF MOMENT CONDITION ESTIMATORS

2014 ◽  
Vol 32 (1) ◽  
pp. 30-70 ◽  
Author(s):  
Xiaohong Chen ◽  
David T. Jacho-Chávez ◽  
Oliver Linton
Keyword(s):  
Moment Condition ◽  
Moment Conditions ◽  
Parameter Heterogeneity ◽  
Class Of Estimators ◽  
Optimal Weighting ◽  
The Mean ◽  
The Moment ◽  
Image Position ◽  
Nonlinear Estimators ◽  
Available Information

We establish the consistency and asymptotic normality for a class of estimators that are linear combinations of a set of$\sqrt n$-consistent nonlinear estimators whose cardinality increases with sample size. The method can be compared with the usual approaches of combining the moment conditions (GMM) and combining the instruments (IV), and achieves similar objectives of aggregating the available information. One advantage of aggregating the estimators rather than the moment conditions is that it yields robustness to certain types of parameter heterogeneity in the sense that it delivers consistent estimates of the mean effect in that case. We discuss the question of optimal weighting of the estimators.

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