• Korean Journal of Digital Imaging in Medicine
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• v.9 no.1
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• pp.37-43
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• 2007

1. Purpose : This study is to present effective exposure conditions to acquire the best image of simple abdomen in Film Screen (F.S) system and Computed Radiography (C.R) system. 2. Method : In the F.S system, while an exposure condition was fixed as 70kVp, images of a patients simple abdomen were taken under the different mAs exposure conditions. Among these images, the best one was chosen by radiologists and radiological technologists. In the C.R system, the best image of the same patient was acquired with the same method from the F.S system. Both characteristic curves from F.S system and C.R system were analyzed. 3. Results : In the F.S system, the best exposure condition of simple abdomen was 70kVp and 20mAs. In the CR system, with the fixed condition at 70kVp, the image densities of human organs, such as liver, kidney, spleen, psoas muscle, lumbar spine body and iliac crest, were almost same despite different environments (3.2mAs, 8mAs, 12mAs, 16mAs and 20mAs). However, when the exposure conditions were over or under (below) 12mAs, the images between the abdominal wall and the directly exposed part became blurred because the gap of density was decreased. In the C.R system, while the volume of mAs was decreased, an artifact of quantum mottle was increased. 4. Conclusion : This study shows that the exposure condition in the C.R system can be reduced 40% than in the F.S system. This paper concluded that when the exposure conditions are set in CR environment, after the analysis of equipment character, such as image processing system(EDR : Exposure Data Recognition processing), PACS and so on, the high quality of image with maximum information can be acquired with a minimum exposure dose.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11b
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• pp.15-17
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• 2004

The quality of X -ray image is depending on the acquired signal pattern So far, the MTF(modulation transfer function) of medical image system has been obtained through various kinds of calculationprocesses after using SWRF (A square wave response function method) to print out it into films. In this study, a tool has been developed that can help the actual user who actually creates the medical images measure the MTF of the finaldisplay image very simply by applying Borland C++ builder software as well as LEAD tools software for the SWRF calculation process to analyze the MTF even on the display image. Films have been printed out by this newly developed MTF measuring tool under the same conditions with the ones for the existing tools and also the calculation method has shown no difference with any existing SWRF calculation method. By using this, it was found out that the MTF of the resolving power of the computed radiography(CR) Image plate (IP) that is a conventional X-ray detection system Jar the conventional X-ray purpose was about 10% at the range of 3.00 LP/mm.

• Journal of radiological science and technology
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• v.37 no.4
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• pp.239-246
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• 2014

Filter absorbs low-energy X-ray to increase the average energy and reduces patient exposure dose. This study investigates if the materials of Mo and W could be used for the digital imaging device CR by conducting image assessment and dose measurement of SNR, FOM and histogram. In addition, measurement of beam quality was conducted depending on the material of the filter, and at the same time, a proper combination of filters was examined depending on the change in tube voltage (kVp). In regard to entrance skin dose, Mo filter showed the dose reduction by 42~56%, compared to Cu filter. Moreover, Mo filter showed higher transmission dose by around 1.5 times than that of Cu filter. In image assessment, it was found that W was unsuitable to be used as a filter, whereas Mo could be used as a filter to reduce dose without decline in image quality at the tube voltage of 80 kVp or higher. As tube voltage increased, 2.0 mm Al+0.1 mm Mo almost had a similar histogram width to that of 2.0 mm Al+0.2 mm Cu. Therefore, Mo filter can be used at relatively high tube voltage of 80 kVp, 100 kVp and 120 kVp. The SNR of 2.0 mm Al+0.1 mm Mo did not show any significant difference from those of 2.0 mm Al+0.2 mm Cu and 2.0 mm Al+0.1 mm Cu. As a result, if Mo filter is used to replace Cu filter in general radiography, where 80 kVp or higher is used for digital radiation image, patient exposure dose can be reduced significantly without decline in image quality, compared to Cu filter. Therefore, it is believed that Mo filter can be applied to chest X-ray and high tube voltage X-ray in actual clinical practice.

• Journal of the Korean Society of Radiology
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• v.6 no.2
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• pp.143-149
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• 2012

Today each hospital is trend that change rapidly by up to date, digitization and introducing newest medical treatment equipment. So, we introduce new CR system and supplement film system's shortcoming and PACS, EMR, RTP system's network that is using in hospital harmoniously and accomplish quality improvement of medical treatment and service elevation about business efficiency enlargement and patient Accordingly, we wish to introduce our case that integrate reflex that happen with radiation oncology here upon to PACS using CR system and estimate the availability. We measured that is Gantry, Collimator Star Shot, Light vs. Radiation, HDR QA(Dwell position accuracy) with Medical LINAC(MEVATRON-MX) Then, PACS was implemented on the digital images on the monitor that can be confirmed through the QA. Also, for cooperation with OCS system that is using from present source and impose code that need in treatment in each treatment, did so that Order that connect to network, input to CR may appear, did so that can solve support data mistake (active Pinacle's case supports DICOM3 file from present source but PACS does not support DICOM3 files.) of Pinacle and PACS that is Planning System and look at Planning premier in PACS. All image and data constructed integration to PACS as can refer and conduct premier in Hospital anywhere using CR system. Use Dosimetry IP in Filmless environment and QA's trial such as Light/Radition field size correspondence, gantry rotation axis' accuracy, collimator rotation axis' accuracy, brachy therapy's Dwell position check is available. Business efficiency by decrease and so on of unnecessary human strength consumption was augmented accordingly with session shortening as that integrate premier that is neted with radiation oncology using CR system to PACS. and for the future patient information security is essential.

• Journal of the Korean Society of Radiology
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• v.6 no.2
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• pp.121-127
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• 2012

Of this study, it was found that there were 250 mammographic units in total installed and used in the areas for this study, and 36 units were used in general hospitals, 53 units in hospitals and 116 units in clinics. That is, the units in clinics accounted for 50% out of the whole units. As for the image acquisition method, it was found there were 131 units using F/S, 67 units using CR and 7 units using DR respectively. At present, F/S system was mainly used in the areas. As for the materials of target/filter, it was found that Mo/Mo was mostly used (66%), followed by Mo/Rh (25%). As for the size of focus, both 0.1 mm for small focus and 0.3 mm for large focus were mainly used for the units.

• Progress in Medical Physics
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• v.14 no.2
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• pp.124-130
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• 2003

Currently, as a consequence of PACS (Picture Archiving Communication System) implementation many hospitals are replacing conventional film-type interpretations of diagnostic medical images with new digital-format interpretations that can also be saved, and retrieve However, the big limitation in PACS is considered to be the lack of mobility. The purpose of this study is to determine the optimal communication packet size. This was done by considering the terms occurred in the wireless communication. After encoding medical image using JPGE2000 image compression method, This method embodied auto-error correction technique preventing the loss of packets occurred during wireless communication. A PC class server, with capabilities to load, collect data, save images, and connect with other network, was installed. Image data were compressed using JPEG2000 algorithm which supports the capability of high energy density and compression ratio, to communicate through a wireless network. Image data were also transmitted in block units coeded by JPEG2000 to prevent the loss of the packets in a wireless network. When JPGE2000 image data were decoded in a PUA (Personal Digital Assistant), it was instantaneous for a MR (Magnetic Resonance) head image of 256${\times}$256 pixels, while it took approximately 5 seconds to decode a CR (Computed Radiography) chest image of 800${\times}$790 pixels. In the transmission of the image data using a CDMA 1X module (Code-Division Multiple Access 1st Generation), 256 byte/sec was considered a stable transmission rate, but packets were lost in the intervals at the transmission rate of 1Kbyte/sec. However, even with a transmission rate above 1 Kbyte/sec, packets were not lost in wireless LAN. Current PACS are not compatible with wireless networks. because it does not have an interface between wired and wireless. Thus, the mobile JPEG2000 image viewing system was developed in order to complement mobility-a limitation in PACS. Moreover, the weak-connections of the wireless network was enhanced by re-transmitting image data within a limitations The results of this study are expected to play an interface role between the current wired-networks PACS and the mobile devices.

• Journal of radiological science and technology
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• v.37 no.1
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• pp.7-14
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• 2014

By using a Chest Phantom(DUKE Phantom) focusing on dose reduction of diagnostic radiation field with the most use of artificial radiation, and attempt to reduce radiation dose studies technical radiation. Publisher of the main user of the X-ray Radiological technologists, Examine the effect of reducing the radiation dose to apply additional filtering of the X-ray generator. In order to understand the organ dose and effective dose by using the PC-Based Monte Carlo Program(PCXMC) Program, the patient receives, was carried out this research. In this experiment, by applying a complex filter using a copper and Al(aluminum,13) and filtered single of using only aluminum with the condition set, and measures the number of the disk of copper indicated by DUKE Phantom. The combination of the composite filtration and filtration of a single number of the disk of the copper is the same, with the PCXMC 2.0. Program looking combination of additional filtration fewest absorbed dose was calculated effective dose and organ dose. Although depends on the use mAs, The 80 kVp AP projection conditions, it is possible to reduce the effective amount of about 84 % from about 30 % to a maximum at least. The 120 kVp PA projection conditions, it is possible to reduce the effective amount of about 71 % from about 41 % to a maximum of at least. The organ dose, dose reduction rate was different in each organ, but it showed a decrease of dose rate of 30 % to up 100 % at least. Additional filtration was used on the imaging conditions throughout the study. There was no change in terms of video quality at low doses. It was found that using the DUKE Phantom and PCXMC 2.0 Program were suitable to calculate the effect of reducing the effective dose and organ dose.