• Journal of the Korean Society of Radiology
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• v.83 no.4
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• pp.876-886
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• 2022

Purpose To evaluate the performance of MicroPure US imaging to detect and characterize microcalcifications. Materials and Methods A total of 171 lesions with suspicious microcalcifications seen on mammography and B-mode US were included and simultaneously evaluated using MicroPure US imaging. The size of microcalcifications was divided into small (punctate, amorphous, fine pleomorphic, and fine linear) and large (coarse heterogeneous), and the extent was divided into narrow (grouped) and wide (others). MicroPure US imaging visibility was divided into four types based on the number of microcalcifications on the two images: B > M (more on B-mode), B = M (similar), B < M (more on MicroPure), and negative. Triple pairwise comparison was used to evaluate the imaging features according to the MicroPure US imaging visibility. Results Among the 171 lesions examined, 157 lesions (91.8%) were detected by MicroPure US imaging. The proportion of Breast Imaging Reporting and Data System (BI-RADS) category 4A was significantly higher in the MicroPure positive group, and that of category 4B was significantly higher in the MicroPure negative group (p = 0.035). The other imaging features did not differ. Among the positive MicroPure subgroups, all features showed no significant difference. Conclusion MicroPure US imaging demonstrated 91.8% positivity in detecting microcalcifications on B-mode US. MicroPure US imaging visibility correlated with the BI-RADS category of microcalcifications.

• Journal of radiological science and technology
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• v.40 no.4
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• pp.575-580
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• 2017

Because moire artifacts overlap with fine lesions and frequency bands, image processing software that removes moire artifacts can lead to loss of micro lesions. In this study, microscopic lesions such as microcalcification and microfracture were randomly formed on SD (Sprague Dawley) rats and image and optimized grid images were compared and analyzed using reference image and grid suppression software. The images were read by two consecutive radiologists using a McNemar's test. Among the 73 microcalcifications, in the 13 cases after grid suppression, the image of the optimized grid shows the loss of image in 3 cases, and the image after grid suppression shows statistically significant image loss (p=0.021). In all 53 fracture lines, there were 19 cases of image loss after the grid suppression, and only one case of the optimized grid showed no image loss. Therefore, the use of grid suppression software to remove moire artifacts should be carefully considered in the diagnosis of micro lesions.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.12
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• pp.1217-1222
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• 2012

A wall flow sensor has been used for feedback flow control and wall shear stress measurement. In this study, we developed a new wall flow sensor by combining the PIV algorithm and the micro image sensor used in an optical mouse. The feasibility of the wall flow sensor was investigated by using simulated fluid flow experiments. Compared with the quadrature signal from imaging devices, the accuracy of the wall flow velocity measurement was improved and the dynamic range increased. In addition, the depth information of particles was also measured by using the defocusing imaging technique.

• Progress in Medical Physics
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• v.22 no.3
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• pp.117-123
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• 2011

Synchrotron radiation (SR) imaging enables us to observe internal structures of biologic samples without staining. In this study, we obtained X-ray microscopic images of human breast tissues with 11.1 KeV hard X-ray microscope of the Pohang light source and used zone plates and phase-contrast technique to get high resolution X-ray images. Hard X-ray microscopic images of fibrocystic change and breast cancer tissues with a spatial resolution of 60 nm were obtained and from these images, we could observe the micro-structures of human breast tissue. Also we analyzed and compared these images, which revealed distinct features of each condition. In conclusion, SR imaging with phase-contrast hard X-ray microscope for medical application, especially in breast disease can give some useful information for clinical research.

• 한국정보교육학회:학술대회논문집
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• 2006.08a
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• pp.247-250
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• 2006

최근 들어 조작이 쉽고 컴퓨터와 연동하여 조작할 수 있다는 장점 때문에 교육 현장에서도 디지털 현미경의 사용이 증가하고 있으나, 이와 관련한 SW의 개발은 국내외적으로 매우 부진한 상황이다. 본 논문에서는 이러한 현미경 영상을 쉽고 효과적으로 분석하기 위한 다기능 영상 측정기 "이미지스코피"를 제안한다. 제안하는 영상 측정기는 일반 영상 편집기의 기능을 제공하면서 미세 영상을 위한 다양한 측정도구도 함께 제공한다. "이미지스코피"는 멀티 레이어 구조의 입체적 편집과, 다양한 영상 형식을 지원하도록 설계하였으며, 미세자를 이용한 측정기준설정과 스프레드시트 연동기능을 갖도록 구현하였다.

• Journal of the Korean Society of Radiology
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• v.82 no.4
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• pp.953-958
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• 2021

High-altitude cerebral edema (HACE) is a potentially fatal neurological syndrome that develops in persons traveling to a high altitude. We report the case of a 49-year-old male who had traveled to a high altitude, and lost consciousness for a few hours. Susceptibility-weighted images revealed multiple, fine black pepper like microbleeds along the corpus callosum with several microbleeds in the left frontal and parietal subcortical white matter. The T2-weighted images did not show any abnormal signal intensities along the corpus callosum. The diffusion-weighted images revealed small nodular high signal intensities in the basal ganglia. This report describes the atypical radiologic findings of HACE showing multiple microbleeds along the corpus callosum, without abnormal high-signal intensity on T2-weighted images.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10a
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• pp.1-5
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• 2006

본 논문에서는 유방암의 조기발견에 있어서 중요한 소견중 하나인 군집화된 미세석회질을 유방촬영 영상으로부터 자동으로 분석 및 검출하는 컴퓨터 보조 검출 시스템을 구현하였다. 전처리단계로서 유방영상에 메디안 필터를 사용하여 잡음을 제거하고, 히스토그램과 레이블링 연산을 수행하여 실제 유방영역만을 추출 하는 작업을 구현하였다. 그런 후에 추출된 실제 유방영역에서 LoG (Laplacian of Gaussian)연산을 수행하고 히스토그램을 분석하여 이진화를 수행한후에 후보점을 검출하였다. 마지막으로 이를 이용하여 영역확장 알고리즘을 수행하여 미세석회질의 후보영역을 검출한 후, 미세석회질간의 거리를 분석하여 최종 관심영역을 추출하였다. 데이터베이스는 총 20개의 MIAS Mini Database의 맘모그램 영상을 사용하였으며 실험결과 89%라는 검출 성능을 얻을 수 있었다.

• The Journal of the Korea Contents Association
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• v.10 no.9
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• pp.259-266
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• 2010

The study focuses on the value of Micro CT, a high resolution X-ray imaging device, by using it on rats to observe the overall portal vein image of the liver and the microvasculature of each lobes, visualize the 4 segmental lobes and acquire 3D image of the microvasculature through the reconstruction of sectional image data. Less of the damage to liver of the 5 mice, the device was able to separate the liver into 4 segmental lobes and displayed the 4 portal vein microvasculature in 2D. By using the 3D MIP technique, observation of the whole portal vein system microvasculature in 3D image was made possible along with each of the portal vein segment's branches until the 6th branch. Measured the size of 6branch, the average was measured at 1branch : $0.51mm{\pm}0.08$, 2 branch : $0.32mm{\pm}0.12$, 3 branch : $0.23mm{\pm}0.11$, 4 branch : $0.19mm{\pm}0.08$, 5 branch : $0.13mm{\pm}0.06$, 6 branch : $70.5{\mu}m{\pm}14.1$. The 3D image and the images of the microvasculatures in the result of study proved that the Micro-CT can be considered many useful device in obtaining high resolution images.

• Investigative Magnetic Resonance Imaging
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• v.12 no.2
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• pp.142-147
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• 2008

Purpose : By using the micro-imaging unit modified from NMR spectrometer, the high resolution MRI protocols of finer than 100 micron in 5 minutes, is sought for mouse, which plays a central role in animal studies Materials and Methods : C57BL/6 mouse, lighter than 50 gram, is used for the experiments. The superconducting magnet is vertical type with 89 mm inner diameter at 4.9 Tesla. The diameter of rf-coil is 30 mm. Mostly used techniques are the fast spin echo and the gradient echo pulse sequence. Results : For 2D images, proton density and T2 weighted images are obtained and their optimum experimental variables were sought. Minute structure of mouse brain can be recognized and 3D brain image is also obtained additionally. 3D image will be useful particularly for the dynamic contrast study using various contrast agents. Conclusion : Like the case of human and other small animals, the high resolution of mouse brain is enough to recognize the minute structure of it. Recently, similar studies are reported domestically, but it seems only a beginning stage. Due to easiness of breeding/control, mouse MRI study will soon play a vital part in brain study.

• Journal of Digital Contents Society
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• v.16 no.2
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• pp.291-298
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• 2015

In a fast-paced information technology environment, consumption of video content is changing from one-way television viewing to VOD (Video on Demand) playing anywhere, anytime, on any device. This video-watching trend gives additional importance to videos with fine-speed-control, in addition to the strength of the digital video signal. Currently, many video players provide a fine-speed-control function which can speed up the video to skip a boring part, or slow it down to focus on an exciting scene. The audio information is just as important as the visual information for understanding the content of the speed-controlled video. Thus, a number of algorithms for fine-speed-control video-playing technologies have been proposed to solve the pitch distortion in the audio-processing area. In this study, well-known techniques for prosodic modification of speech signals, WSOLA (Waveform-Similarity-Based Overlap-Add), have been applied to analyze users' needs for fine-speed-control video playing. By surveying the users' preferred speeds on categorized video content and analyzing the results, this paper proposes that various fine-speed adjustments are needed to accommodate users' preferred video consumption.