• Investigative Magnetic Resonance Imaging
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• v.21 no.4
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• pp.233-241
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• 2017

Purpose: To report on the current practices in breast magnetic resonance imaging (MRI) in Korea. Materials and Methods: We invited the 68 members of the Korean Society of Breast Imaging who were working in hospitals with available breast MRI to participate in a survey on how they performed and interpreted breast MRI. We asked one member from each hospital to respond to the survey. A total of 22 surveys from 22 hospitals were analyzed. Results: Out of 22 hospitals, 13 (59.1%) performed at least 300 breast MRI examinations per year, and 5 out of 22 (22.7%) performed > 1200 per year. Out of 31 machines, 14 (45.2%) machines were 1.5-T scanners and 17 (54.8%) were 3.0-T scanners. All hospitals did contrast-enhanced breast MRI. Full-time breast radiologists supervised the performance and interpreted breast MRI in 19 of 22 (86.4%) of hospitals. All hospitals used BI-RADS for MRI interpretation. For computer-aided detection (CAD), 13 (59.1%) hospitals sometimes or always use it and 9 (40.9%) hospitals did not use CAD. Two (9.1%) and twelve (54.5%) hospitals never and rarely interpreted breast MRI without correlating the mammography or ultrasound, respectively. The majority of respondents rarely (13/21, 61.9%) or never (5/21, 23.8%) interpreted breast MRI performed at an outside facility. Of the hospitals performing contrast-enhanced examinations, 15 of 22 (68.2%) did not perform MRI-guided interventional procedures. Conclusion: Breast MRI is extensively performed in Korea. The indication and practical patterns are diverse. The information from this survey would provide the basis for the development of Korean breast MRI practice guidelines.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.423-428
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• 2019

The role of angioembolization has increased because of increases in nonoperative treatment for traumatic splenic injury. We report here a case of successful treatment of iatrogenic pseudoaneurysm of the femoral artery by thrombin injection with coil embolization. A 55-year-old female was admitted to our hospital because of blunt trauma. Computed tomography (CT) revealed a grade V splenic injury with contrast extravasation; therefore, angioembolization was performed. Three days after admission, follow-up CT scan revealed rebleeding from the spleen, and repeat angioembolization was performed. Seven days after admission, an approximately $7.0cm{\times}4.0cm-sized$ pseudoaneurysm was found on follow-up CT scan and there was no bleeding from the spleen. Although thrombin was injected into the aneurysmal sac, there was still inflow of blood, as observed on color-doppler ultrasound. Therefore, coil embolization to the neck of the aneurysm was performed. On angiography, there was no contrast filling into the sac. The size of the pseudoaneurysmal sac had decreased on follow-up CT scan, and the patient was discharged to home without complications. We successfully treated a giant pseudoaneurysm of the femoral artery using thrombin and coil embolization.

• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.375-384
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• 2023

Most Hepatic hemangiomas are asymptomatic and small in size, making them difficult to find by pathological examination. Therefore, radiological diagnosis is essential for the early finding and diagnosis of Hepatic hemangioma. Three-phase method using contrast medium in computed tomography, T1, T2-weighted imaging in magnetic resonance imaging, dynamic magnetic resonance imaging using contrast medium, echo planar imaging method, diffusion-weighted imaging method, blood pool scan using ^99mTc-labeled red blood cells in nuclear medicine, we looked at the color doppler method In ultrasound, and it is important to accurately understand the imaging findings of hepatic hemangioma and perform the examination in order to make an accurate diagnosis. most hepatic hemangioma are benign tumors, care should be taken not to confuse them with malignant tumors such as hepatocellular carcinoma to prevent unnecessary procedures. Therefore, in order to make an accurate diagnosis, it is important to accurately understand the imaging findings of hemangioma and perform the examination.

• Journal of the Korea Society of Computer and Information
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• v.16 no.2
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• pp.55-60
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• 2011

In this paper, we propose a new method for extracting muscles from lumbar images. The proposed method sets areas without distortions with field expert's assistance as areas of measuring interest and removing noises from initial ultrasonic videos. Then, the method emphasizes the brightness contrast with Ends-in search stretching algorithm and separate thoracic vertebra from subcutaneous fat area using morphological characteristics. 4-directions contour tracing algorithm is applied to extract the bottom of subcutaneous fat area. Extracting thoracic vertebra area requires noise removal and morphological characteristics as well among candidate areas obtained by controlling min-max brightness. The thickness of muscles is then defined as the length between subcutaneous fat area and extracted thoracic vertebra. The experiment which consists of 368 image analysis verifies that the proposed method is more effective in measuring the thickness of muscles than before.

• The Journal of the Acoustical Society of Korea
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• v.24 no.5
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• pp.282-293
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• 2005

Sonoelastography is an ultrasound-based technique that visualizes the elastic properties of soft tissues by measuring the tissue motion generated by an externally applied vibration. In this paper. the characteristics of wave generation in soft tissues due to an acoustic vibrator are studied. The effects of modal patterns on the detectability of lesions such as tumors in senoelastography are also investigated These are accomplished by analyzing the vibration patterns calculated using theoretical equations and finite element methods in halt space, infinite plate. and finite-sized tissue. A finite-width source generates shear waves with large amplitude Propagating in specific directions. and the generation characteristics depend both on the width and frequency of the vibrator. as well as the distance from it. It is shown in a finite-sized tissue that the lesion detection in displacement images is quit dependent on the modal patterns inside tissue. In contrast it Is also found that the lesion detectability in strain images is less dependent on the modal Patterns and is much better than that in displacement images.

• Tuberculosis and Respiratory Diseases
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• v.76 no.2
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• pp.88-92
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• 2014

We hereby report a case on bronchogenic cyst which is initially non-infected, then becomes infected after bronchoscopic ultrasound (US)-guided transesophageal fine-needle aspiration (FNA). The non-infected bronchogenic cyst appears to be filled with relatively echogenic materials on US, and the aspirate is a whitish jelly-like fluid. Upon contrast-enhanced MRI of the infected bronchogenic cyst, a T1-weighted image shows low signal intensity and a T2-weighted image shows high signal intensity, with no enhancements of the cyst contents, but enhancements of the thickened cystic wall. The patient then undergo video-assisted thoracic surgery 14 days after the FNA. The cystic mass is known to be completely removed, and the aspirate is yellowish and purulent. To understand the image findings that pertain to the gross appearance of the cyst contents will help to diagnose bronchogenic cysts in the future.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.3
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• pp.341-346
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• 2012

In rehabilitation where ultrasonographic diagnosis is not popular, it could be subjective by medical expert's experience. Thus, it is necessary to develop an objective automative procedure in ultrasonic image analysis. A disadvantage of existing automative analytic procedure in musculoskeletal system is to designate an incorrect muscle area when the figure of fascia is vague. In this study, we propose a new procedure to extract more accurate muscle area in abdomen ultrasonic image for that purpose. After removing unnecessary noise from input image, we apply End-in Search algorithm to enhance the contrast between fascia and muscle area. Then after extracting initial muscle area by Up-Down search, we trace the fascia area with a mask based on morphological and directional information. By this tracing of mask movements, we can emphasize the fascia area to extract more accurate muscle area in result. This new procedure is proven to be more effective than existing methods in experiment using convex ultrasound images that are used in real world rehabilitation diagnosis.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup2
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• pp.322-327
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• 2001

Objectives : There are many kinds of method to evaluate neural decompression during operation. They are direct visual and manual inspection, intraoperative ultrasound, endoscope, intraoperative computed tomography and intraoperative myelography. We used intraoperative myelography to evaluate the proper decompression of neural elements during the decompressive surgery. Methods : We injected 10-20cc of nonionic water-soluble contrast materials through direct puncture site of exposed dura during operation or lower lumbar level or lumbar drain inserted preoperatively. 12 patients were included in this study. They were 7 patients of centrally herniated lumbar disc disease, 1 patient of multiple lumbar spinal stenosis, 2 patients of thoracic extradural tumor and 2 cervical fracture & dislocations. Results : 5 of 12 patients showed remained neural compression through intraoperative myelography, so they were operated further through other approach. Myelographic dye is heavier than CSF, so the dependent side of subarachnoid space was visualized only. In one case, CSF leakage through hemovac was detected, but it was treated only bed rest for 5 days after hemovac removal. Conclusion :Intraoperative myelography is an effective method to evaluate neural decompression during spinal surgery. This technique is easy and familiar to us, neurosurgeons.

• Journal of the Korea Computer Graphics Society
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• v.25 no.3
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• pp.31-41
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• 2019

A fog screen consists of tiny water drops and the viewers see the image transmitted through the fog screen. In contrast to ordinary screens, the viewers can see the actors passing through the image on the fog screen on stage. In this paper, we describe methods to build a top-down fog screen where fog particles generated in top space fall by gravity forming a flat vertical screen. We use a fog generation technique in which fog particles come out of the water surface when ultrasound vibrators immersed in water tank vibrate. We describe how fog particles form a flat screen while coming out of the fog passage tunnel, by generating guiding winds beside the fog screen. This technique utilizes the principle that fog particles are generated on the surface of a water tank by an ultrasonic vibrator placed in a water tank. The technique of forming a guiding wind on both sides of the passage exit where the fog comes out and the design and manufacturing method of the fog screen generating device are described so that the generated fog group can maintain one plane.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.6
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• pp.865-871
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• 2022

In this paper, we propose a method of extracting prostate region using morphological characteristics of ultra-sonic image of prostate. In the first step of the proposed method, the edge area of the prostate image is extracted. The histogram of ultra-sonic image is used to extract base objects to detect the upper edge of prostate region by altering the contrast of the image, then, the lower edges of the extracted base objects are connected by using monotone cubic spline interpolation to extract the upper edge. Step 2, Otsu's binarization is applied to the region under the extracted upper edge of the prostate ultra-sonic image to extract the lower edge of prostate. In the last step, the upper and the lower edges are connected to extract prostate region and by comparing the extracted region of prostate with the one measured manually, the result showed that the morphological characteristics of prostate in ultrasonic image can be utilized to extract the prostate region.