• Clinical Endoscopy
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• v.55 no.1
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• pp.113-121
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• 2022

Background/Aims: We have been developing artificial intelligence based polyp histology prediction (AIPHP) method to classify Narrow Band Imaging (NBI) magnifying colonoscopy images to predict the hyperplastic or neoplastic histology of polyps. Our aim was to analyze the accuracy of AIPHP and narrow-band imaging international colorectal endoscopic (NICE) classification based histology predictions and also to compare the results of the two methods. Methods: We studied 373 colorectal polyp samples taken by polypectomy from 279 patients. The documented NBI still images were analyzed by the AIPHP method and by the NICE classification parallel. The AIPHP software was created by machine learning method. The software measures five geometrical and color features on the endoscopic image. Results: The accuracy of AIPHP was 86.6% (323/373) in total of polyps. We compared the AIPHP accuracy results for diminutive and non-diminutive polyps (82.1% vs. 92.2%; p=0.0032). The accuracy of the hyperplastic histology prediction was significantly better by NICE compared to AIPHP method both in the diminutive polyps (n=207) (95.2% vs. 82.1%) (p<0.001) and also in all evaluated polyps (n=373) (97.1% vs. 86.6%) (p<0.001) Conclusions: Our artificial intelligence based polyp histology prediction software could predict histology with high accuracy only in the large size polyp subgroup.

• Applied Microscopy
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• v.45 no.1
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• pp.23-31
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• 2015

Dark field (DF) transmission electron microscopy image has become a popular characterization method for two-dimensional material, graphene, since it can visualize grain structure and multilayer islands, and further provide structural information such as crystal orientation relations, defects, etc. unlike other imaging tools. Here we present microstructure of graphene, particularly, using DF imaging. High-angle grain boundary formation wass observed in heat-treated chemical vapor deposition-grown graphene on the Si substrate using patch-quilted DF imaging processing, which is supposed to occur by strain around multilayer islands. Upon the crystal orientation between layers the multilayer islands were categorized into the oriented one and the twisted one, and their local structure were compared. In addition information from each diffraction spot in selected area diffraction pattern was summarized.

• The Korean Journal of Nuclear Medicine
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• v.34 no.1
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• pp.1-9
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• 2000

The rapid progress of molecular genetic methods over the past two decades has necessitated the development of methods to detect and quantify genetic activity within living bodies. Reporter genes provide a rapid and convenient tool to monitor gene expression by yielding a readily measurable phenotype upon expression when introduced into a biological system. Conventional reporter systems, however, are limited in their usefulness for in vivo experiments or human gene therapy because of its invasive nature which requires cell damage before assays can be performed. This offers an unique opportunity for nuclear imaging techniques to develope a novel method for imaging both the location and amount of gene expression noninvasively. Current developments to achieve this goal rely on utilizing either reporter enzymes that accumulate radiolabeled substrates or reporter receptors that bind specific radioligands. This overview includes a brief introduction to the background for such research, a summary of published results, and an outlook for future directions.

• Journal of Multimedia Information System
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• v.3 no.3
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• pp.47-52
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• 2016

This research paper examines the usage of graphic imaging in Holographic Projections to further advance the medical field. It highlights the importance and necessity of this technology as well as avant-garde techniques applied in the process of displaying images in digital holography. This paper also discusses the different types of applications for holograms in society today. Different tools were utilized to transfer a set of a cancer patient's brain tumor data into data used to produce a 3D holographic image. This image was produced through the transfer of data from one program to another. Through the use of semi-automatic segmentation through the seed region method, we were able to create a 3D visualization from Computed Tomography (CT) data.

• Korean Journal of Optics and Photonics
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• v.15 no.2
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• pp.130-136
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• 2004

We investigate characteristics of viewing resolution improvement in three-dimensional integral imaging, when a dynamic lens array method is adopted. We show that the viewing resolution changes for different moving directions and distances of the lens array through computer-synthesized integral imaging. From this study, optimal moving conditions of the lens array for efficient viewing resolution improvement can be determined.

• Journal of the Optical Society of Korea
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• v.18 no.6
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• pp.714-719
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• 2014

A pico-projector is a compact and mobile projector that has an infinite focus. We apply the pico-projector to a projection-type integral imaging system, which can expand the image depth to form multiple central depth planes. In a projection-type integral imaging system, the image flipping problem arises because the expanded elemental images pass through a lens array. To solve this problem, we propose the ray tracing of a pico-projector at a central depth plane and compensate the elemental image using a pixel-mapping process. Experiments to verify the proposed method are performed, and the results are presented.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.sup1
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• pp.157-161
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• 2008

Malignant pleural mesothelioma (MPM) has a poor prognosis and a strong association with exposure to asbestos. Although there are not generally accepted guidelines for treatment of MPM, recent reports suggest that multi modality therapy combining chemotherapy, radiotherapy, and surgery can improve the survival of patients with MPM. Therefore exact staging is required to decide the best treatment option. However, it is well known that there are many difficulties in determining precise preoperative stage, predicting prognosis, and monitoring response to therapy with conventional imaging modalities such as CT and MRI in MPM. Recently PET with $^{18}F-FDG$ comes into the spotlight as an important staging method. There is increasing evidence that PET is superior to other conventional imaging modalities in diagnosis and staging of MPM. Particularly PET/CT improves the diagnostic and staging accuracy over PET or CT alone in MPM because it provides anatomic imaging data as well as functional information. PET and PET/CT are also useful for monitoring response to therapy and SUV is reported as a prognostic factor in MPM.

• The Korean Journal of Nuclear Medicine
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• v.39 no.2
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• pp.107-113
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• 2005

Pharmacologic stress testing for myocardial perfusion imaging is a widely used noninvasive method for the evaluation of known or suspected coronary artery disease. The use of exercise for cardiac stress has been practiced for over 60 years and clinicians are familial with its using. However, there are inevitabe situations in which exorcise stress is inappropriate. A large number of patients with cardiac problems are unable to exercise to their full potential due to comorbidity such as osteoarthritis, vascular disease and pulmonary disease and a standard exercise stress test for myocardial perfusion imaging is suboptimal means for assessment of coronary artery disease. This problem has led to the development of the pharmacologic stress test and to a great increase in its popularity. All of the currently used pharmacologic agents have well-documented diagnostic value. This review deals the physiological actions, clinical protocols, safety, nuclear imaging applications of currently available stress agents and future development of new vasodilating agents.

• Proceedings of the KOSOMBE Conference
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• v.1993 no.05
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• pp.45-48
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• 1993

High-order field gradients are useful for spatial localization of a volume of interest and dynamic range improvement of signal detection in NMR (Nuclear Magnetic Resonance) spectroscopy and imaging. This paper proposes a design method of shielded high-order gradient coils to reduce tile effect of eddy current on tile spectroscopy and imaging results. According to the experimental results, the shielded gradient coils produce less than 2 % eddy current compared to non-shielded coils. Two shielded $z^2$ gradient coils have been designed and constructed for 1.5 T whole-body and 3.0 T animal NMR imaging systems. Experimental results are in good agreement with the theoretically expected behavior and show the utility of the shielded high-order gradient coils.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1350-1353
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• 2009

Conventional depth extraction in integral imaging is based on the disparity information between the elemental images. Since the disparity is measured in pixel unit, however, the extracted depth is discrete, resulting in the quantization error. Moreover, the quantization error grows as the object depth increases, which limits the accuracy of the depth extraction for distant objects. In this paper, we propose a new method for depth extraction in integral imaging using sub-pixel registration information between subimages to obtain linear and accurate depth.