• Imaging Science in Dentistry
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• v.52 no.2
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• pp.181-186
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• 2022

Purpose: This study aimed to investigate inter-observer reliability among observers with different levels of proficiency and the diagnostic imaging reliability of cone-beam computed tomography (CBCT) images of the retromolar canal. Materials and Methods: CBCT images of 307 patients were assessed for the presence of retromolar canals(RMCs) by 3 observers independently. Diagnoses were made twice by each observer at intervals of more than 3 weeks. Interobserver reliability was assessed using the kappa coefficient. One observer had no experience in diagnosis using CBCT images. Therefore, a specialist in diagnostic imaging explained the CBCT images for interpretation and practiced diagnostic imaging together with this observer, while the other observer interpreted the images independently. Thereafter, the observers re-evaluated the images. Results: The interobserver kappa coefficients (including bilateral RMCs) calculated at the first reading were low, ranging from 0.21 to 0.61. Their values ranged from 0.95 (right side) to 1.00 (left side) after one-on-one practice with a diagnostic imaging specialist, while the values ranged from 0.65 (right side) to 0.66 (left side) without one-on-one practice. Conclusion: Diagnostic accuracy was improved through diagnostic imaging practice. To improve the anatomical interpretation of images, it is important to practice diagnostic imaging with a specialist in diagnostic imaging. One-on-one instruction about diagnostic imaging was an effective method of training.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.3 no.1
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• pp.25-31
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• 2017

Liposomes are defined as spherical, self-closed structures formed by lipid bilayers containing aqueous phase. Most liposomes are composed of various amphipathic lipids such as phospholipids and cholesterol. We used amphipathic lipids (DPPC, DPPG) as liposome components and prepared around 100 nm liposomes by standard extrusion method. Nuclear/MR dual imaging agents based on liposome platform were prepared by adding radioactive $^{131}I$-HIB (hexadecyl-4-tributylstannylbenzoate) and Gd-DTPA into liposome bilayer and inside liposome, respectively. Gamma camera and MR imaging both showed signal increases in liver.

• Journal of Biomedical Engineering Research
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• v.28 no.1
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• pp.102-107
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• 2007

In molecular imaging studies via magnetic resonance imaging, in vivo cell tracking is an important issue for the observation of cell therapy or disease behavior. High resolution imaging and longitudinal study are necessary to track the cell movement. Since the field inhomogeneity extends over several voxels, we have performed the numerical analysis using the sub-voxel method dividing a voxel of MR image into several elements and the information about the field inhomogeneity distribution around the micro-beads. We imbedded ferrite-composite micro-beads with the size of $20-150{\mu}m$ in the subject substituted for cells to induce local field distortion. In the phantom imaging with the isotropic voxel size of $200{\mu}m^3$, we could confirm the feasibility of sub-voxel tracking in a 3.0 T MRI.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.2
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• pp.56-64
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• 1996

In the previous paper of this study, an incoherent intensity pattern of a conducting cylinder is obtained by averaging out the multi-frequency intensities of the time-harmonic fields scattered from this cylinder. in this paper, an incoherent imaging of a conducting cylinder is obtained via the back-projection of the incoherent intensity patterns calculated from the circular rotational measurement configuration. This imaging method is vlaidated by imaging a conducting circular and a conducting elliptic cylinder and the measurement conditions to get better image are investigated.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.937-938
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• 2008

Spotlight system has been made use of art works on stage such as musical and performance etc. Currently, spotlight is controlled manually through the planned path in advance. Therefore, automatic control system is necessary for manipulating spotlight on stage. In this paper, we propose the system that detects to track the multiple objects and classifies those objects, also selects an object of those ones. The proposed method can be applied to the interactive stage spotlighting system(ISSS).

• Molecules and Cells
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• v.39 no.12
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• pp.841-846
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• 2016

Local protein synthesis mediates precise spatio-temporal regulation of gene expression for neuronal functions such as long-term plasticity, axon guidance and regeneration. To reveal the underlying mechanisms of local translation, it is crucial to understand mRNA transport, localization and translation in live neurons. Among various techniques for mRNA analysis, fluorescence microscopy has been widely used as the most direct method to study localization of mRNA. Live-cell imaging of single RNA molecules is particularly advantageous to dissect the highly heterogeneous and dynamic nature of messenger ribonucleoprotein (mRNP) complexes in neurons. Here, we review recent advances in the study of mRNA localization and translation in live neurons using novel techniques for single-RNA imaging.

• ETRI Journal
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• v.31 no.2
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• pp.105-110
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• 2009

In this paper, we propose a curved projection integral imaging system to improve the horizontal and vertical viewing angles. The proposed system can be easily implemented by additional use of a large-aperture convex lens in conventional projection integral imaging. To obtain the simultaneous display of 3D images through real and virtual image fields, we propose a computer-generated pickup method based on ray optics and elemental images, which are synthesized for the proposed system. To show the feasibility of the proposed system, preliminary experiments are carried out. Experimental results indicate that our system improves the viewing angle and displays 3D images simultaneously in real and virtual image fields.

• 한국가시화정보학회:학술대회논문집
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• 2002.11a
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• pp.31-34
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• 2002

Imaging techniques using x-ray beam at high energies (>6KeV) such as contact radiography, projection microscopy, and tomography have been used to nondestructively discern internal structure of objects in material science, biology, and medicine. This paper introduces the x-ray micro-imaging method using 1B2 micro-probe line of PAL (Pohang Accelerator Laboratory). Cross-sectional information on low electron density materials can be obtained by probing a sample with coherent synchrotron x-ray beam in an in-line holography setup. Living organism such as plants, insects are practically transparent to high energy x-rays and create phase shift images of x-ray wave front. X-ray micro-images of micro-bubbles of $20\~120\;{\mu}m$ diameter in an opaque tube were recorded. Clear phase contrast images were obtained at Interfaces between bubbles and surrounding liquid due to different decrements of refractive index.

• Parasites, Hosts and Diseases
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• v.45 no.2 s.142
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• pp.77-85
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• 2007

Among several diagnostic tools for clonorchiasis (Clonorchis sinensis infection), radiologic examinations are commonly used in clinical practices. During the 2 past decades, many reports regarding imaging findings of clonorchiasis were introduced. The basic imaging finding of clonorchiasis is diffuse dilatation of the peripheral intra-hepatic bile ducts, without dilation of the large intrahepatic or extrahepatic bile ducts. By this finding, however, active clonorchiasis cannot be differentiated from cured infection. Some recent radiologic studies suggested specific findings of active clonorchiasis. Besides direct demonstration of worms, increased periductal echogenicity on sonography and periductal enhancement on dynamic contrast-enhanced CT or MR imaging possibly represent active clonorchiasis. Those images of the liver clonorchiasis are known to be correlated with worm burdens (EPG counts) in their frequency and also severity. The images of cholangiocarcinoma associated with clonorchiasis show both the tumor with obstruction images and diffuse dilatation of the peripheral intrahepatic bile ducts. Radiological images can be a good practical alternative diagnostic method of clonorchiasis.

• Communications of the Korean Mathematical Society
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• v.16 no.3
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• pp.519-541
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• 2001

Magnetic Resonance Electrical Impedance Tomography(MREIT) is a new medical imaging technique for the cross-sectional conductivity distribution of a human body using both EIT(Electrical Impedance Tomography) and MRI(Magnetic Resonance Imaging) system. MREIT system was designed to enhance EIT imaging system which has inherent low sensitivity of boundary measurements to any changes of internal tissue conductivity values. MREIT utilizes a recent CDI (Current Density Imaging) technique of measuring the internal current density by means of MRI technique. In this paper, a mathematical modeling for MREIT and image reconstruction method called the alternating J-substitution algorithm are presented. Computer simulations show that the alternating J-substitution algorithm provides accurate high-resolution conductivity images.