• Journal of radiological science and technology
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• v.32 no.1
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• pp.53-60
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• 2009

This study examined the change in the attenuation of X-rays with the ROI (Region of Interest) in DR (Digital Radiography) according to the stomach contents by manufacturing a tissue equivalent material phantom to simulate real stomach tissue based on the assumption that there is some attenuation of X-rays and a difference in imaging quality according to the stomach contents. The transit dosage by the attenuation of X-rays decreased with increasing protein thickness, which altered the average ROI values in the film and DR images. A comparison of the change in average ROI values of the film and DR image showed that the image in film caused larger density changes with varying thickness of protein than the image by DR. The results indicate that NPO (nothing by mouth) is more important in film system than in DR system.

• Korean Journal of Digital Imaging in Medicine
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• v.12 no.2
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• pp.81-87
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• 2010

The setting parameters of ultrasound scanner give influences to change of image. Sonographers have used a Matlab program to make Low Contrast Sensitivity(LCS) value and compared original images in order to evaluate the use of the supersonic diagnosis machinery. We confirmed the change of image in Grayscale values using Photoshop program. Experiment equipment of our research used A Medison Accuvix V10, A Multi-Tissue Ultrasound Phantom(040 GSE) of CHRIS Company, A Adobe Photoshop CS4 Program, A Convex Probe, A USB memory stick, A Probe Fixation Equipment. The method used Gain, Dynamic Range(DR) of the setting parameters of ultrasound scanner and researched Gain and DR was set to 10 dB. We changed the different settings to see the changes of images using Grayscale values of a Photoshop program about tissue images of a phantom. This study evaluated DR and Gain whether it is an image controller to get the optimum contrast to produce an image to see the how effect on the images. We did not use Gateway in supersonic diagnosis machinery. We can easily open to open the files through Photoshop program before we get Digital Imaging and Communications in Medicine(DICOM) files use USB memory stick in supersonic diagnosis machinery. When we diagnosed the lesion of the patient with ultrasound, the contrast and the Gray scale value of image are very important. In this research, we determined the optimum setting parameters that provided useful information to diagnose disease and evaluated the change of improved images.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.7
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• pp.1737-1742
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• 2015

In the industrial field for product inspection needs not only on the surface of the product but also the internal components defect inspection. Generally, optical inspection is mainly used for item inspection from production process. However, this is only to check defect of surface it is difficult to perform inspection of goods internal. To overcome these limitations, Instead of optical device by using the portable X- ray DR image acquisition device system developed to obtain an image in real time at the same time and determine product defects. After obtaining the X- ray image, the inspection product within error range is passed after machine image processing. Also, the results and numbers are stored by users.

• Journal of the Korea Computer Graphics Society
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• v.13 no.2
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• pp.55-60
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• 2007

Diminished reality (DR) is a technique that provide a visual convenience by virtually hiding an object. Most of existing DR systems have been implemented based on HMDs or desktop displays. However, Here has been no report on the development of DR system based on projection displays due to technical difficulty in spite of its superiority in the aspect of human factor to conventional displays. Rapid advances of projection displays and projection-based vision technologies motivated us to develop a projection-based DR system. As the first attempt, this paper proposes a projection-based diminished reality system using an image completion technique. Its usefulness is demonstrated through experiments and its potential applications are discussed.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.436-436
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• 2006

• Journal of radiological science and technology
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• v.35 no.4
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• pp.309-314
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• 2012

Nowadays, digital Radiography (DR) systems are widely used in clinical sites and substitute the analog-film x-ray imaging systems. The resolution of DR images depends on several factors such as characteristic contrast and motion of the object, the focal spot size and the quality of x-ray beam, x-ray scattering, the performance of the DR detector (x-ray conversion efficiency, the intrinsic resolution). The DR detector is composed of an x-ray capturing element, a coupling element and a collecting element, which systematically affect the system resolution. Generally speaking, the resolution of a medical imaging system is the discrimination ability of anatomical structures. Modulation transfer function (MTF) is widely used for the quantification of the resolution performance for an imaging system. MTF is defined as the frequency response of the imaging system to the input of a point spread function and can be obtained by doing Fourier transform of a line spread function, which is extracted from a test image. In clinic, radiologic technologists, who are in charge of system maintenance and quality control, have to evaluate or make routine check on their imaging system. However, it is not an easy task for the radiologic technologists to measure MTF accurately due to lack of their engineering and mathematical backgrounds. The objective of this study is to develop and provide for radiologic technologists a medical system imaging evaluation tool, so that they can measure and quantify system performance easily.

• Imaging Science in Dentistry
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• v.32 no.3
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• pp.129-134
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• 2002

Purpose : To implement the database system of oral and maxillofacial radiological images using a commercial medical image management software with personally developed classification code. Materials and methods : The image database was built using a slightly modified commercial medical image management software, Dr. Image v.2.1 (Bit Computer Co., Korea). The function of wild card '*' was added to the search function of this program. Diagnosis classification codes were written as the number at the first three digits, and radiographic technique classification codes as the alphabet right after the diagnosis code. 449 radiological films of 218 cases from January, 2000 to December, 2000, which had been specially stored for the demonstration and education at Dept. of OMF Radiology of Dankook University Dental Hospital, were scanned with each patient information. Results: Cases could be efficiently accessed and analyzed by using the classification code. Search and statistics results were easily obtained according to sex, age, disease diagnosis and radiographic technique. Conclusion : Efficient image management was possible with this image database system. Application of this system to other departments or personal image management can be made possible by utilizing the appropriate classification code system.

• Korean Journal of Digital Imaging in Medicine
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• v.12 no.2
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• pp.133-138
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• 2010

The purpose of this study was to survey and test quality control of mammography system. The conclusion of this study is as follows ; First, The rate of pass for phantom image test shows that Film-Screen mammography system(F/S) and computed mammography system(CR) is 80%, Indirect digital mammography system(DR) is 100%. Second, The test of exposure dose shows that F/S is 921 mR. CR is 1,140 mR, DR is 474 mR. The grade of this testament is CR > F/S > DR. Third, The test of average glandular dose shows that F/S is 1,336 mGy, CR is 1,635 mGy, DR is 1,26 mGy. The grade of this testament is CR > F/S > DR. Fourth, The testament of resolution shows as follows F/S is 11~13 Lp/mm, CR is 4~5 Lp/mm, and DR is 5~7 Lp/mm(F/S > DR > CR) Fifth, The survey of projection, cassette, development and reading shows that user are indifference.

• Journal of the Korean Society of Radiology
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• v.13 no.1
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• pp.81-86
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• 2019

In X-ray image, the role of filtration through the filter is to reduce the exposure of the patient by using photon which is useful in formation of the image, and at the same time, enhance the contrast of the image. During interaction between photon and object, low energy X-rays are absorbed from the site of a few cm of the first patient's tissue, and high energy X-rays are the one which form the image. Therefore, the radiation filter absorbs low energy X-ray in order to lower the exposure of the patient and improve the quality of the image. The purpose of this study is to compare the effect on the image quality by differences of added filter through simulation image and actual radiation image. For that purpose, we used Geant4 Application for Tomographic Emission (GATE) as a tool for Monte Carlo simulation. We set actual size, shape and material of Polymethylmethacrylate (PMMA) Phantom on GATE and differentiated the parameter of added filter. Also, we took image of PMMA phantom with same parameter of added filter by digital radiography (DR). Than we performed contrast-to-noise ratio (CNR) evaluation on both simulation image and actual DR image by Image J. Finally, we observed the effect on image quality due to different thickness of added filter, and compared two images' CNR evaluation's transitions of change. The result of this experiment showed decreasing in the progress of CNR on both DR and simulation image. It is ultimately caused by decreasing in contrast on image. In theory, contrast decrease with kVp increased. Given that condition, this study found out that filter makes not only decreasing total dose by absorbing low energy of X-ray, but also increasing average energy of X-ray.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.25 no.3
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• pp.340-346
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• 2023

Bilateral distal anterior cerebral artery (DACA) aneurysms also called "kissing aneurysms" or "mirror aneurysm" are extremely rare, accounting for only 0.2% of all intracranial aneurysms. There have only been a few examples of mirror DACA aneurysms reported in the literature. Here, we report a rare case of mirror DACA aneurysm in a middle aged female with its successful clipping. Patient was admitted with severe headache and altered sensorium. Computed tomography (CT) head was suggestive of anterior inter-hemispheric hematoma. Digital subtraction angiography (DSA) was done which was suggestive of two distal anterior cerebral artery aneurysms located at same anatomical position. It was treated through microsurgical clipping. Mirror image DACA aneurysms are rare occurrence. All patients with ruptured DACA aneurysms should have angiography with 3D reconstruction studies. This aids in determining the aneurysm's morphology and planning treatment accordingly.