• Journal of KIISE:Software and Applications
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• v.30 no.12
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• pp.1247-1254
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• 2003

Currently. the north american symptomatic carotid endarterectomy trial, european carotid surgery trial, and common carotid method are used to measure the carotid stenosis for determining candidate for carotid endarterectomy using the projection angiography from different modalities such as digital subtraction angiography. rotational angiography, computed tomography angiography and magnetic resonance angiography. A new computerized carotid stenosis measuring system was developed using MR angiography axial image to overcome the drawbacks of conventional carotid stenosis measuring methods, to reduce the variability of inter-observer and intra-observer. The gray-level thresholding is one of the most popular and efficient method for image segmentation. We segmented the carotid artery and lumen from three-dimensional time-of-flight MRA axial image using gray-level thresholding technique. Using the measured intima-media thickness value of common carotid artery for each cases, we separated carotid artery wall from the segmented carotid artery region. After that, the regions of segmented carotid without artery wall were divided into region of blood flow and plaque. The calculation of carotid stenosis degree was performed as the following; carotid stenosis grading is(area measure of plaque/area measure of blood flow region and plaque) * 100%.

• Journal of the Korean Society for Nondestructive Testing
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• v.31 no.5
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• pp.479-486
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• 2011

In image-based CFD modeling of carotid bifurcation hemodynamics, it is often not possible (or at least not convenient) to impose measured velocity profiles at the common carotid artery inlet. Instead, fully-developed velocity profiles are usually imposed based on measured flow rates. However, some studies reported a pronounced influence of inflow boundary conditions that were based on actual velocity profiles measured by magnetic resonance imaging which showing the unusual presence of a high velocity band in the middle of the vessel during early diastole inconsistent with a Dean-type velocity profile. We demonstrated that those velocity profiles were induced by the presence of modest secondary curvature of the inlet and set about to test whether such more "realistic" velocity profiles might indeed have a more pronounced influence on the carotid bifurcation hemodynamics. We found that inlet boundary condition with axisymmetric fully-developed velocity profile(Womersley flow) is reasonable as long as sufficient CCA inlet length of realistic geometry is applied.

• Journal of Advanced Navigation Technology
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• v.17 no.1
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• pp.115-122
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• 2013

Disease diagnostics based on medical imaging is getting popularity day by day. Presence of the atherosclerosis is one of the causes of narrowing of carotid arteries which may block partially or fully blood flow into the brain. Serious brain strokes may occur due to such types of blockages in blood flow. Early detection of the plaque and taking precautionary steps in this regard may prevent from such type of serious strokes. In this paper, we present an automatic image segmentation technique for carotid artery ultrasound images based on active contour approach. In our experimental study, we assume that ultrasound images are properly aligned before applying automatic image segmentation. We have successfully applied the automatic segmentation of carotid artery ultrasound images using snake based model. Qualitative comparison of the proposed approach has been made with the manual initialization of snakes for carotid artery image segmentation. Our proposed approach successfully segments the carotid artery images in an automated way to help radiologists to detect plaque easily. Obtained results show the effectiveness of the proposed approach.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.1104-1107
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• 2011

경동맥 내중막 두께는 심혈관계 질환의 위험인자와 상관성이 높으므로 경동맥 내중막 영상 분석을 통해 심혈관계 질환의 1차 검진 방법으로 사용이 가능하다. 이 논문에서는 내중막 영상에서 이상지질혈증의 진단지표가 될 수 있는 특징벡터 추출 방법을 제안하였으며, 패턴기반, 함수기반의 분류모델 생성과 평가를 통해 추출된 진단 지표가 이상지질혈증 분류에 적합함을 검증하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.188-193
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• 2019

Transarterial chemoembolization (TACE) is a commonly used and rapidly evolving non-invasive treatment for hepatocellular carcinoma (HCC). It is important that understanding individual anatomical variants and planning for tumor-feeding artery access to acquire adequate treatment effectiveness. In this study, we will report acquired arteriovenous malformation which interferes with TACE for HCC. A 72-year-old man with persistent abdominal pain for 2 days visited our hospital. The patient was chronic hepatitis B carrier and had a history of HCC treated with conventional TACE 10 years ago. Hypervascular nodular HCC in the liver segment 8 and aberrant right hepatic artery from the superior mesenteric artery were detected on computed tomography (CT). When first TACE was performed, the tumor-feeding artery originating from the left hepatic artery was found and embolized. There was no tumor-feeding artery from the right hepatic artery but arteriovenous malformation was found. After a month, follow up CT showed necrotic lesion and residual HCC and we performed secondary TACE. On secondary TACE, we selected the right hepatic artery and passed through arteriovenous malformation. Superselective-angiogram showed remnant tumoral staining and remnant tumor was embolized using drug-eluting bead and Adriamycin. Final angiogram showed no remnant tumoral staining and the patient was discharged without complication. We found the rare case of arteriovenous malformation adjacent to HCC, and we performed superselective TACE beyond arteriovenous malformation to treat HCC.

• Journal of KIISE:Software and Applications
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• v.30 no.9
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• pp.821-828
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• 2003

The virtual angioscopy was implemented using MR angiography image of carotid artery Inside of the carotid artery is one of the body region not accessible by real optical endoscopy but can be visualized with virtual endoscopy. In order to determine the navigation path, we segmented the common carotid artery and internal carotid artery from the MR angiography image. We used the coordinates as a navigation path for virtual camera that were calculated from medial axis transformation. We used the perspective projection and marching cube algorithm to render the surface from volumetric MRA image data. A stroke occurs when brain cells die because of decreased blood flow to the brain. The carotid artery is the primary blood vessel that supplies the blood flow to the brain. Therefore, the carotid artery stenosis is the primary reason of stroke. The virtual angioscopy is highly recommended as a diagnosis tool with which the specific Place of stenosis can be identified and the degree of stenosis can be measured qualitatively. Also, the virtual angioscopy can be used as an education and training tool for endoscopist and radiologist.

• Journal of the Korea Society for Simulation
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• v.16 no.1
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• pp.21-29
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• 2007

In this paper, we present a method of detecting the boundary of the intima-media complex for automated measurement based on dynamic programming from carotid artery B-mode ultrasound images and then show the experimental results. We apply the dynamic programming for determining the optimal locations that a cost function is minimized. The cost function includes cost terms which are representing image features such as intensity, intensity gradient and geometrical continuity of the vessel interfaces. Moreover, we improve the boundary continuity by applying the B-spline to smooth the rough boundary due to noise such as speckle, dropout and weak edges. The proposed method has obtained more accurate reproducible results than conventional edge-detection by considering multiple image features and ensures efficient automated measurement by solving the problems of the inter- and intra-observer variability and its inefficiency due to manual measurement.

• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.465-472
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• 2023

In predicting vascular disease, this study attempted to identify changes in the carotid intima-media thickness in patients who underwent carotid artery ultrasonography and hematological tests and to find out the effect of risk factors on the expression of atherosclerotic plaque. A retrospective analysis was conducted on 469 healthy adults who visited the hospital for the purpose of medical examination and performed carotid artery ultrasonography. As a result, carotid intima-media thickness, age, body mass index, waist circumference, systolic blood pressure, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and glucose were analyzed as significant predictors of atherosclerotic plaque (p<0.001). The risk ratio was calculated based on the cut off value of the risk factors of the atherosclerotic plaque determined through ROC curve analysis, followed by 8.06 times the carotid intima-media thickness, 7.53 times the age, 3.97 times the waist circumference and 2.02 times the glucose. Therefore, in this study it was possible to prepare a Korean standard for clinical risk factors that affect the presence of absence of atherosclerotic plaque and observation of carotid artery ultrasonography is thought to help diagnose or predict cardiovascular disease early.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.43 no.5 s.311
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• pp.89-100
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• 2006

The carotid intima-media thickness (IMT) is very important, because the severity of it is an independent predictor of transient cerebral ischemia, stroke, and coronary events such as myocardial infarction. The conventional image processing to measure the IMT has not been satisfactory, because the methods have relied on the manual section drawing and a regional segmentation by differential estimation. We propose a new image processing technology effective to extract features from the carotid artery image whose pixels have the directional vector properties with composed color distribution. The technique we presented here is not by differential variation but by verification of the layer properties of carotid artery image. Iterated vertical and horizontal analysis and segmentation of the IMT image show the vector characteristics. This new technique makes it possible to cluster the layers statistically, and to classify mathematical correlation between regions and resulting in correct measurements of thickness and its variation. The advantages and effectiveness of this approach are applicable to region process and character extraction of such a vector image.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.289-290
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• 2022

Arteriosclerosis is a disease in which the carotid vessel wall becomes thick, and it is important to monitor the thickness of the vessel wall for diagnosis. In this study, we propose a model for extracting 324 radiomics features from carotid MRI images and diagnosing arteriosclerosis using machine learning techniques. We learned a total of four classification models: logistic regression, support vector machine, random forest, and XGBoost through radiomics features. XGBoost model, which showed the highest performance in 5-fold cross-validation, shows the results of accuracy 0.9023, sensitivity 0.9517, specificity 0.8035, AUC 0.8776.