• Journal of the Institute of Convergence Signal Processing
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• v.15 no.4
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• pp.128-134
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• 2014

In this paper, we propose a detection method of the leukocyte motions in a microvessel by using spatiotemporal image analysis. The leukocyte motions that adhere to blood vessel walls can be visualized to move along the blood vessel wall's contours in a sequence of images. In this proposal method, we use the constraint that the leukocytes move along the blood vessel wall's contours and detect the leukocyte motions by using the spatiotemporal image analysis method. The generated spatiotemporal image is processed by a special-purpose orientation-selective filter and then subsequent grouping processes are done. The subsequent grouping processes select and group the leukocyte trace segments among all the segments obtained by simple thresholding and skeletonizing operations. Experimental results show that the proposed method can stably detect the leukocyte motions even when multiple leukocyte traces intersect each other.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.6
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• pp.91-96
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• 2010

A laser speckle is a random pattern that has a granular appearance produced by reflected light when a coherent laser illuminates an irregular course surface. Laser speckle system has many advantages. It can detect some animals functional parts. Moreover, it relatively consists of simple and in-expensive system. It is very important that detecting micro-vessels through image processed image. Current study is to improve image quality through variable image processing method. But this paper made laser speckle endoscope for miniaturization and commercialization laser speckle system. We had endoscope test through goldfish's tail. We will compare the processed speckle image and halogen image.

• Journal of Biomedical Engineering Research
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• v.16 no.3
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• pp.289-300
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• 1995

The conventionally used method requires centerline of vessels to estimate the vessel diameter. Two methods of estimating the centerline of vessels are reported : One is manually observer-defined method. This potentially contributes to inter-and intra-observer variability. And the other is to auto- matically detect the centerline of vessels. But this is very complicated method. In this paper, we propose a new method of estimating vessel diameter using direction codes and position informs:ion without detecting centerline. Since this method detects the vessel boundary and direction code at d same time, it simplifies the procedure and reduces execution time in estimating the vessel diameter. Compared to a method that automatically estimates the vessel diAmeter uslng centerline, our method provides improved accuracy in image with poor contrast, branching or obstructed vessels. Also, this provides a good compression of boundary description, because each direction code element can be coded with 3 bits only, instead of the 4 bytes required for the storage of the coordinates of each border pixel. Our experiments demonstrate the usefulness of the technique using direction code for quantitative analysis of coronary angiography Experimental results Justify the validity of the proposed method.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.9
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• pp.99-109
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• 2016

This paper presents a method for generating spatiotemporal images to detect the leukocyte motions in a microvessel. By using the constraint that the leukocytes move along the contour line of a blood vessel wall, the method detects leukocyte motions and then generates spatiotemporal images. the translational motion by a movement in vivo is removed first by the template matching method. Next, a blood vessel region is detected by the automatic threshold selection method to binarize the temporal variance image, then a blood vessel wall's contour is expressed by B-spline function. With the detected blood vessel wall's contour as an initial curve, the plasma layer of the best accurate position is determined to be the spatial axis by snake. Finally, the spatiotemporal images are generated. The experimental results show the spatiotemporal images are generated effectively through the comparison of each step of three image sequences.

• Journal of the Korean Society of Radiology
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• v.17 no.4
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• pp.551-556
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• 2023

Angiography equipment is used to evaluate and treat coronary artery disease. As a common feature of equipment, radiation is used, and function development for dose reduction is being carried out by each company. Therefore, the difference depending on whether DCR installed in angiography equipment is used is analyzed from a radiological point of view to prove the effect. Among 431 patients who underwent coronary artery intervention from March 2021 to February 2023, 250 patients with retrospective data were selected. And than among the 250 subjects obtained, 91 patients used the cardiovascular roadmap function during single-vessel intervention, and 159 patients did not use the roadmap. When DCR was used, total dose area product (34.57 uGy/m² : 69.15 uGy/m²), total air kerma dose (688.47 mGy : 1640.4 mGy), fluoroscopy dose (23.87 uGy/m² : 49.91 uGy/m²) and fluoroscopy time (723.55 s : 366.03 s), total number of images (17 : 26) showed lower values and were statistically significant than those not used. The use of DCR function in single vessel coronary intervention is thought to be radiologically safer as single vessel coronary intervention using dynamic cardiovascular DCR showed lower perspective time and perspective dose than procedures performed without the DCR.

• Progress in Medical Physics
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• v.23 no.3
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• pp.177-187
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• 2012

Magnetic resonance angiography (MRA) techniques are widely used in diagnosis of vascular disorders such as hemadostenosis and aneurism. Especially, phase contrast (PC) MRA technique, which is a typical non contrast-enhanced MRA technique, provides not only the anatomy of blood vessels but also flow velocity. In this study, we developed the 2- and 3-dimensional PC MRA pulse sequences for a low magnetic field MRI system. Vessel images were acquired using 2D and 3D PC MRA and the velocities of the blood flow were measured in the superior sagittal sinus, straight sinus and the confluence of the two. The 2D PC MRA provided the good quality of vascular images for large vessels but the poor quality for small ones. Although 3D PC MRA gave more improved visualization of small vessels than 2D PC MRA, the image quality was not enough to be used for diagnosis of the small vessels due to the low SNR and field homogeneity of the low field MRI system. The measured blood velocities were $25.46{\pm}0.73cm/sec$, $24.02{\pm}0.34cm/sec$ and $26.15{\pm}1.50cm/sec$ in the superior sagittal sinus, straight sinus and the confluence of the two, respectively, which showed good agreement with the previous experimental values. Thus, the developed PC MRA technique for low field MRI system is expected to provide the useful velocity information to diagnose the large brain vessels.

• Advances in pediatric surgery
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• v.19 no.2
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• pp.108-121
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• 2013

목적 Pheochromocytoma of the Adrenal gland Scaled Score (PASS) 시스템과 면역화학염색 등을 통한 갈색세포종 및 부교감신경절종의 악성화 예측인자가 제시되고 있으나 명확한 병리학적 또는 분자생물학적 예측인자는 밝혀진 바 없다. 본 연구에서는 임상적, 병리학적 분석을 통해 갈색세포종 및 복강내 부교감신경절종의 악성화 예측인자를 확인하고자 하였다. 대상 및 방법 1990년 1월부터 2010년 12월까지 서울대학교어린이병원에서 수술적 절제 후 병리학적으로 갈색세포종 및 복강내 부교감신경절종으로 확진된 20명의 18세 이하 소아 환자를 대상으로 임상적 특징을 분석하였고, PASS 시스템에 따른 병리 슬라이드 판독하였다. 세포활성도를 반영한다고 알려진 유전자에 대한 항체 중 Ki-67, p53, bcl-2, mdm-2, cycline D1, p21, p27을 이용해 면역 화학검사를 한 후 결과를 확인하였다. 결과 20명의 환자 중 갈색세포종은 14명, 복강내 부교감신경절종은 6명이었다. 악성화는 각각 4명, 3명에서 관찰되었다. 혈관 침범, 주변부 지방조직 침습, 세포분열 증가가 통계적으로 유의한 악성화 예측인자였으며(각각 p=.007, .031, .031), 갈색세포종만 분석하였을 때도 통계적으로 유의하였다(각각 p=.033, .003, .019). PASS 시스템은 악성화를 예측하는데 있어 통계적으로 유의하지 않았으며, 혈관 침범, 주변부 지방조직 침습, 세포분열 증가를 항목으로 하여 새롭게 만든 병리 스코어 시스템은 악성 환자군과 양성 환자군 사이에 통계적으로 유의한 차이를 보였다(p< .001). 악성과 양성 질환 사이의 면역화학염색 결과에서 유의한 차이는 없었다. 결론 소아에서 갈색세포종 및 복강내 부교감신경절종의 악성화 예측인자로 혈관 침범, 주변부 지방조직 침습, 세포분열 증가를 이용할 수 있다. 소아에서 PASS시스템으로 악성화를 예측할 수 없었으나, 새로운 병리스코어 시스템으로 악성 환자군을 예측할 수 있었다. 면역화학검사 결과 세포 활성도를 반영하는 인자들은 악성화를 예측할 수 없었다.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.4
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• pp.546-554
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• 1996

Vscularized calvarial bone flaps have been useful tools in the reconstuction of different type of bone defects in craniofacial surgery Vascularized bone transfer are often preferred to nonvascularized bone grafts because nonvascularized bone grafts are less resistant to infection, not as mechanically strong, and do not survive well in a poorly vascularized bed. Potential advantages of vascularized outer table calvarial bone flap include proximity to the operative field, membranous origin similar to that of the facial skeleton, maleability which allows for a variety of shapes and sizes, inconspicous donor sit scar. The following are the case reports of two patients who underwent craniofacial reconstruction suing vascularized outer table calvarial bone flap.

• The Journal of the Acoustical Society of Korea
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• v.37 no.4
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• pp.215-222
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• 2018

This paper reports the development and performance evaluation of a backend system for real-time IVUS (Intravascular Ultrasound) imaging. The developed backend system was designed to minimize the amount of logic and memory usage by means of efficient LUTs (Look-up Tables), and it was implemented in a single FPGA (Field Programmable Gate Array) without using external memory. This makes it possible to implement the backend system that is less expensive, smaller, and lighter. The accuracy of the backend system implemented was evaluated by comparing the output of the FPGA with the result computed using a MATLAB program implemented in the same way as the VHDL (VHSIC Hardware Description Language) code. Based on the result of ex-vivo experiment using rabbit artery, the developed backend system was found to be suitable for real-time intravascular ultrasound imaging.

• Journal of the Korean Society of Radiology
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• v.83 no.4
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• pp.958-964
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• 2022

Pulmonary epithelioid hemangioendothelioma (PEH) is a rare vascular tumor of borderline or low-grade malignancy, and its prognosis is unpredictable. Herein, we describe the case of a 47-year-old asymptomatic female with a diagnosis of multinodular PEH. During a 7-year follow-up, the nodules with large size and high ¹⁸F-fluorodeoxyglucose uptake in the initial study showed progression with increasing sizes; however, most small nodules (size < 1 cm) demonstrated spontaneous regression with peripheral rim or nodular calcification. The patient underwent surgical resection for an enlarged nodule. Of note, it is unusual for an individual to have mixed progression and regression concomitantly, which may be helpful in predicting the prognosis.