• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.3207-3209
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• 2000

X-ray CT(Computed Tomography) has been a good modality for non-invasive diagnosis and recently, Conventional CT has been replaced rapidly with Spiral CT in recent. In X-ray CT, spiral scanning has various advantages such as better image quality, reduced scan time (in a single breath-hold), a lower x-ray dose. But, it requires very fast and high performance image processing system to reconstruct slice images from spiral scanning. This paper describes the fast image reconstruction techniques with filtered back projection from the viewpoints of fast algorithm as well as hardware implementation for real-time imaging.

• Journal of the Korean Society for Nondestructive Testing
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• v.18 no.3
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• pp.181-190
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• 1998

A computerized tomography system was developed using the X-ray source that has diameter of 5 micrometer. The system is used for the nondestructive testing of specimens with diameter below 20 mm. The convolution back projection algorithm was adopted for the reconstruction of cross sectional image, and the shape of the X-ray beam was let parallel beam or fan beam to compare each resultant image. Our CT system was constructed to operate based on the personal computer. The sectional images of the fabricated specimens were reconstructed and analyzed. The reconstructed images well coincided with real images taken with optical microscope and gave us enough reports on the defects in the ceramic specimen. The resolution of the system regarded as about $20{\sim}30$ micrometers.

• Journal of the Korean Society of Radiology
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• v.18 no.3
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• pp.301-307
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• 2024

The Study Evaluated Radiography Images using the Mastoid Process Axial Oblique Projection (Arcelin) imaging method for the Diagnosis of Pyramid Ridge, Mastoid Process, Mastoid Process air cells, Tympanum, Internal auditory and petrous in Supine Position. The subjective ROC (receiver operation characteristic) evaluation method was conducted on five Radiological technologists who have worked in the Image medical Department of University Hospitals for more than 8 years, and the Objective Evaluation, signal-to-noise Ratio (SNR), was evaluated and Analyzed. The Cronbach Alpha value was significantly higher at 0.816. In the Image ROC Evaluation Taken by Tilting the X-ray Tube 5°, 10°, 15° toward the leg by 10°, it Scored 34 points, and in the overall evaluation, the SNR scored high at 6,549. In Addition, In the Image Evaluation taken by Tilting the X-ray Tube 5°, 10°, and 15° toward the head, it Scored 32 points In the Image ROC Evaluation taken by tilting 5°, and in the Objective Evaluation, SNR received the highest score of 6,732.

• Journal of Biomedical Engineering Research
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• v.26 no.5
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• pp.295-300
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• 2005

We introduce an x-ray micro tomography system capable of high resolution imaging of a local region inside a small animal. By combining two kinds of projection data, one from a full field-of-view (FOV) scan of the whole body and the other from a limited FOV scan of the region of interest, we have obtained zoomed-in images of the region of interest without any contrast a nomalies. We have integrated a micro tomography system using a micro-focus x-ray source, a $1248\times1248$ flat-panel x-ray detector, and a precision scan mechanism. Using the cross-sectional images taken with the zoom-in micro tomography system, we measured trabecular thicknesses of femur bones in postmortem rats. To compensate the limited spatial resolution in the zoom-in micro tomography images, we used the fuzzy distance transform for the calculation of the trabecular thickness. To validate the trabecular thickness measurement with the zoom-in micro tomography images, we compared the measurement results with the ones obtained from the conventional micro tomography images of the extracted bone samples.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.8
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• pp.1151-1156
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• 2013

In this study, to clearly establish the concept of a geometric modeling I apply for the concept of Pushbroom, limited to two-dimensional radiation Locator to provide a three-dimensional information purposes. Respect to the radiation scanner Pushbroom modeling techniques, geometric modeling method was presented introduced to extract three-dimensional information as long as the rotational component of the Gamma-Ray Linear Pushbroom Stereo System, introduced the two-dimensional and three-dimensional spatial information in the matching relation that can be induced. In addition, the pseudo-inverse matrix by using the conventional least-squares method, GCP(Ground Control Point) to demonstrate compliance by calculating the key parameters. Projection transformation matrix is calculated for obtaining three-dimensional information from two-dimensional information can be used as the primary relationship, and through the application of a radiation image matching technology will make it possible to extract three-dimensional information from two-dimensional X-ray imaging.

• Journal of the Korean Society of Radiology
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• v.9 no.5
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• pp.301-306
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• 2015

X-ray can be applied to obtain a projection image of an object. It is not easy to obtain an high quality image for the object composed of low and high density materials. For the object with large difference in density, it is possible to realize high contrast image using images of low and high tube voltages and image processing. The plastic and metalic parts of the electronic components can be imaged by the dual energy technique which use low and high tube voltages and by processing pixel-by-pixel using visual C++. The contrast-enhanced image can be used to detect and observe defects within the electronic components.

• Journal of the Korean Society of Radiology
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• v.14 no.4
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• pp.477-486
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• 2020

The purpose of this study was to evaluate the effects of reconstruction filters, X-ray source trajectories and intervals in the quality of digital tomosynthesis (DT) images, and the results was clinically validated. The filtered back-projection was implemented by using Ramp, Shepp-Logan, Cosine, Hamming, Hann and Blackman filters, and the X-ray source trajectories were simulated with 1 × 36, 2 × 18, 3 × 12, 4 × 9 and 6 × 6 arrays. The X-ray source intervals were 5, 10, 20, 30 and 40 mm. The depth resolution, spatial resolution and noise of DT image were evaluated by measuring artifact spread function (ASF), full width at half maximum (FWHM) and signal-to-noise ratio (SNR), respectively. The results showed that the spatial resolution and noise properties of DT images were maximized by the Ramp and Blackman filters, respectively, and the depth resolution and noise properties of the DT images obtained with a 1 × 36 X-ray source trajectory were superior to the other trajectories. The depth resolution and noise properties of DT images improved with an increase of X-ray source intervals, and the high X-ray source intervals degraded the spatial resolution of DT images. Therefore, the characteristics of DT images are highly dependent on reconstruction filters, X-ray source trajectories and intervals, and it is necessary to use optimal imaging parameters in accordance with diagnostic purpose.

• Journal of the Korean Society of Radiology
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• v.12 no.3
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• pp.397-402
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• 2018

The study best image for diagnosis of fracture, dislocation and unilateral degenerative arthritis of the Sacroiliac joint, this study was performed to obtain the best image of the joint space of the hip joint by giving angle change to the pelvis phantom and the x-ray tube. I received evaluation. The results of the Receiver Operating Characteristic that in the case of simple photographs for the detection of joint arthritis and degenerative arthritis in the prone position, the photograph taken in the prone position raises the buttocks of the opposite side of the test by $25^{\circ}{\sim}30^{\circ}$ and the x-ray tube is perpendicular to the sagittal plane passing 2.5 cm inward from the thorny vertebra In the lying position, lift the Sacroiliac joint of the test side by $25^{\circ}{\sim}30^{\circ}$, and take a $5^{\circ}$ angle of the x-ray tube angle toward the foot toward the center of the upper bruch spine from it will be helpful to diagnose arthritis. the center of the upper bruch spine to the side of the ankle joints in the transverse direction And posterior direction, it will be helpful to diagnose arthritis.

• Journal of radiological science and technology
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• v.23 no.1
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• pp.21-27
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• 2000

To evaluation of patients who have shoulder impingement syndrome is by diagnostic radiography. Shoulder impingement is a problem which occurs in young, active individuals as well as older individuals. In fact, the pain is probably caused by repetitive stress placed on the shoulder joint either through recreational activities of your occupation. Impingement series approach to radiographic examination of the shoulder is take five projections. First anteroposterior oblique projection. Second standard anteroposterior projection. Third superoinferior axial projection. Fourth supraspinatus outlet projection offers a view of the outlet of the supraspinatus tendon unit as it passes under the coraacromial arch. Fifth anteroposterior $30^{\circ}$ caudal projection will adequately demonstrate the anterior acromial spur or ossification in the coraacromial ligament and more reliable to demonstrate spurring of the anterior acromion than supraspinatus outlet projection. This decreased the need for additional radiographic veiws, reduces the patient's exposure to x - ray radiation and decreases use of film. This can lower the cost of the evaluation and improve patient satisfaction.

• Journal of radiological science and technology
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• v.19 no.2
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• pp.59-65
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• 1996

We studied exposure techniques and exposure dose for simple abdomen A-P projection for 41 medical facilities that are located in Seoul area. 1. The range of tube voltage used was 60 to 84 kVp, the average tube voltage used was 74 kVp 2. Only 17% of added filter was used. 3. Tube current mostly used was 200 mA, some of them used 400 mA. 4. The grid ratio mostly was used 10 : 1, 54 % of the rare earth screen was used in most facilities. 5. The average skin entrance dose was 4.15 mSv and the dose range was 1.05 mSv to 11.0 mSv.