• Imaging Science in Dentistry
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• v.40 no.4
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• pp.155-158
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• 2010

Digital radiographic systems allow the implementation of a fully digital picture archiving and communication system (PACS), and provide the greater dynamic range of digital detectors with possible reduction of X-ray exposure to the patient. This article reviewed the basic physical principles of digital radiographic imaging system in dental clinics generally. Digital radiography can be divided into computed radiography (CR) and direct radiography (DR). CR systems acquire digital images using phosphor storage plates (PSP) with a separate image readout process. On the other hand, DR systems convert X-rays into electrical charges by means of a direct readout process. DR systems can be further divided into direct and indirect conversion systems depending on the type of X-ray conversion. While a direct conversion requires a photoconductor that converts X-ray photons into electrical charges directly, in an indirect conversion, lightsensitive sensors such as CCD or a flat-panel detector convert visible light, proportional to the incident X-ray energy by a scintillator, into electrical charges. Indirect conversion sensors using CCD or CMOS without lens-coupling are used in intraoral radiography. CR system using PSP is mainly used in extraoral radiographic system and a linear array CCD or CR sensors, in panoramic system. Currently, the digital radiographic system is an important subject in the dental field. Most studies reported that no significant difference in diagnostic performance was found between the digital and conventional systems. To accept advances in technology and utilize benefits provided by the systems, the continuous feedback between doctors and manufacturers is essential.

• Journal of radiological science and technology
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• v.30 no.1
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• pp.47-51
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• 2007

Development of hospital information system and Picture Archiving Communication System is not new in the medical field, and the development of internet and information technology are also universal. In the course of such development, however, it is hard to share medical information without a refined standard format. Especially in the department of radiology, the role of PACS has become very important in interchanging information with other disparate hospital information systems. A specific system needs to be developed that radiological reports are archived into a database efficiently. This includes sharing of medical images. A model is suggested in this study in which an internal system is developed where radiologists store necessary images and transmit them in the standard international clinical format, Clinical Document Architecture, and share the information with hospitals. CDA document generator was made to generate a new file format and separate the existing storage system from the new system. This was to ensure the access to required data in XML documents. The model presented in this study added a process where crucial images in reading are inserted in the CDA radiological report generator. Therefore, this study suggests a storage and transmission model for CDA documents, which is different from the existing DICOM SR. Radiological reports could be better shared, when the application function for inserting images and the analysis of standard clinical terms are completed.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.38 no.4
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• pp.39-49
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• 2001

Application of information system to hospital would bring innovative improvement on efficiency of business management and provide high quality services toward patients as well as the retrenchment of operating funds. PACS(Picture Archiving and Communication System) including X-ray film that manages the medical image information effectively, has drawn considerable attention to essential structural elements to the sophisticated information system for hospital. PACS system should be connected to the network after making a form of standard medical image file from different style of image information obtained from various medical instruments. In this paper, to solve this problem, we construct Mini-PACS that converts the form of Non-DICOM file to the form of standard file by designing the DICOM converter. This system is designed to be managed under Web environment. Comparing with the existed Mini-PACSs, consisting of the client and server module, our system is designed and implemented with integration of these functions in order to be strongly combine strongly between system.

• The KIPS Transactions:PartC
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• v.17C no.2
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• pp.173-180
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• 2010

Information technology is being applied to the development of ubiquitous healthcare system, which provides both efficient patient care and convenient treatment regardless of patient's location. However, the increasing number of users and medical information give rise to the problem of user management and the infringement of privacy. In order to address this problem we propose a user access scheme based on the RBAC (Role Based Access Control) model. The preceding trust management model for Grid security, FAS(Federation Agent Server), was analyzed and extended to provide supplementary functions for role-based access control in u-Healthcare system. The RBAC model provides efficient user management and access control, but very vulnerable in case when one with valid role tries to leak confidential inner medical information. In order to resolve this problem, a RBAC-WS (Work Status with RBAC) model has been additionally developed which allows only qualified staffs to access the system while on duty. Th proposed RBAC and RBAC-WS model have been merged together and applied to the PACS (Picture Archiving and Communication System).

• Progress in Medical Physics
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• v.19 no.1
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• pp.63-72
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• 2008

With recent advancement of the medical imaging systems and picture archiving and communication system (PACS), installation of digital radiography has been accelerated over past few years. Moreover, Computed Radiography (CR) which was well established for the foundation of digital x-ray imaging systems at low cost was widely used for clinical applications. This study analyzes imaging characteristics for two systems with different pixel sizes through the Modulation Transfer Function (MTF), Noise Power Spectrum (NPS) and Detective Quantum Efficiency (DQE). In addition, influence of radiation dose to the imaging characteristics was also measured by quantitative assessment. A standard beam quality RQA5 based on an international electro-technical commission (IEC) standard was used to perform the x-ray imaging studies. For the results, the spatial resolution based on MTF at 10% for Agfa CR system with I.P size of $8{\times}10$ inches and $14{\times}17$ inches was measured as 3.9 cycles/mm and 2.8 cycles/mm, respectively. The spatial resolution based on MTF at 10% for Fuji CR system with I.P size of $8{\times}10$ inches and $14{\times}17$ inches was measured as 3.4 cycles/mm and 3.2 cycles/mm, respectively. There was difference in the spatial resolution for $14{\times}17$ inches, although radiation dose does not effect to the MTF. The NPS of the Agfa CR system shows similar results for different pixel size between $100{\mu}m$ for $8{\times}10$ inch I.P and $150{\mu}m$ for $14{\times}17$ inch I.P. For both systems, the results show better NPS for increased radiation dose due to increasing number of photons. DQE of the Agfa CR system for $8{\times}10$ inch I.P and $14{\times}17$ inch I.P resulted in 11% and 8.8% at 1.5 cycles/mm, respectively. Both systems show that the higher level of radiation dose would lead to the worse DQE efficiency. Measuring DQE for multiple factors of imaging characteristics plays very important role in determining efficiency of equipment and reducing radiation dose for the patients. In conclusion, the results of this study could be used as a baseline to optimize imaging systems and their imaging characteristics by measuring MTF, NPS, and DQE for different level of radiation dose.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.5
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• pp.315-323
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• 2005

The recent development of embodiment technology of the medical images makes most medical institutions introduce PACS in haste. However, while many older HIS and PACS systems are not yet capable of some of the integration, several new systems are moving rapidly in that direction. Typical PACS system architecture begins with the HIS since this is where the correct patient demographic information and in many cases the orders originate. So, PACS developed convenience of users and to satisfy user's demand because of financial limitations and administrator-oriented considerations in the process of development. Therefore, we have developed a CDA (Clinical Document Architecture) based PACS with HIS, by which we can search and refer to the patient's medical images and information with few restrictions of time and space for diagnosis and treatment. Target model of this research limited to 135 of hospital have 200 beds. We'll make more effort to develop the application which insures the better quality and information of medical images. Medical Image History manages the patient's image files and various medical informations like film chart in connection with time. This trial will contribute to the reduction of the financial loss caused by unnecessary devices and improve the quality in the medical services. The demand on the development of the program which refers to the medical data quickly and keeps them stable will be continued by the medical institute. This will satisfy the client's demand and improve the service to the patients in that the program will be modified from the standpoint of the users.

• The Journal of the Korea Contents Association
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• v.8 no.12
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• pp.20-27
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• 2008

Hospitals today use independent systems for each department and job such as Hospital Information Sytem(HIS), Picture Archiving Communications System(PACS), Ordering Communication System(OCS), Electronic Medical Record(EMR), Enterprise Resource Planning(ERP), etc and each system employs its own DB. So, it is impossible to integrate information within the institution and difficult to keep transparency and consistency of data. I in this study offered a data integration environment through flexible management linked with other systems, and by doing that, designed a medical CRM frame which offers the optimum service the customer wants at the optimum time. I designed 4 of medical CRM frame: customer relationship management, public relations/marketing, service management, and statistics/analysis by the customer relationship management process standardization and aimed to offer tailored mobile contents according to customer's characters and health situation on the basis of customer's data by securing mobile medical contents for personalized medical information service.

• Journal of radiological science and technology
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• v.29 no.4
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• pp.241-247
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• 2006

Recently, interests and utilization on Computed Radiography(CR) and Digital Radiography(DR) tends to increase owing to an introduction of Picture Archiving and Communication System(PACS) and an accuracy control of special medical equipment for a breast imaging examination. This study was intended to compare and analyze a detector's imaging quality by each system to be used for the breast imaging examination by using ACR Phantom used at the accuracy control. As an evaluation method, a significance and reliability of image's value using the ACR Phantom was analyzed by using SPSS program. The results are followed. 1. For the fiber, there was 3.9 score in Screen-Film, 4.2 score in CR($50{\mu}m$), 3.2 score in CR($100{\mu}m$), and 4.2 score in DR. There was the high score in the order of CR($50{\mu}m$), DR, Screen-Film, and CR($100{\mu}m$)(P<0.05). 2. For the calcification, there was 2.7 score in Screen-Film, 2.5 score in CR($50{\mu}m$), 2.0 score in CR($100{\mu}m$), and 2.9 score in DR. There was the high score in the order of DR, Screen-Film, CR($50{\mu}m$), and CR($100{\mu}m$).(0.025(P<0.05). 3. For Mass, there was 3.8 score in Screen-Film, 3.8 score in CR($50{\mu}m$), 3.6 score in CR($100{\mu}m$), and 4.5 score in DR. There was the high score in the order of DR, CR($50{\mu}m$), Screen-Film, and CR($100{\mu}m$) (P<0.1). 4. As the total score, there was 10.4 score in Screen-Film, 10.6 score in CR($50{\mu}m$), 8.7 score in CR($100{\mu}m$), and 11.3 score in DR. There was the high score in the order of DR, $CR(50{\mu}m$), Screen-Film, and $CR(100{\mu}m$). As shown in the above results, it can be known that DR and Screen-Film System has higher image quality than CR. But, DR has unstability caused by element, and Screen-Film has the low image quality caused by artifact as disadvantages. When Dual-Side CR($50{\mu}m$) was used among CR systems which had the problem of low image quality, it was indicated that there was no difference with Screen-Film System. Because the radiation imaging examination tends to become digitalized, each system for the breast imaging examination will need to be developed and supplemented.

• Imaging Science in Dentistry
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• v.45 no.3
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• pp.175-180
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• 2015

Purpose: This study was performed to evaluate the reliability of the identification of anatomical landmarks in panoramic and lateral cephalometric radiographs on a standard medical grade picture archiving communication system (PACS) monitor and a tablet computer (iPad 5). Materials and Methods: A total of 1000 radiographs, including 500 panoramic and 500 lateral cephalometric radiographs, were retrieved from the de-identified dataset of the archive of the Section of Oral and Maxillofacial Radiology of the University Of Connecticut School Of Dental Medicine. Major radiographic anatomical landmarks were independently reviewed by two examiners on both displays. The examiners initially reviewed ten panoramic and ten lateral cephalometric radiographs using each imaging system, in order to verify interoperator agreement in landmark identification. The images were scored on a four-point scale reflecting the diagnostic image quality and exposure level of the images. Results: Statistical analysis showed no significant difference between the two displays regarding the visibility and clarity of the landmarks in either the panoramic or cephalometric radiographs. Conclusion: Tablet computers can reliably show anatomical landmarks in panoramic and lateral cephalometric radiographs.

• The Transactions of the Korea Information Processing Society
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• v.5 no.11
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• pp.2776-2785
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• 1998

An image retrieval system based on image content is a key issue for building and managing large multimedia database, such as art galleries and museums, trademarks and copyrights, and picture archiving and communication system. Therefore, the interest on the subject of content-based image retrieval has been greatly increased for the last few years. This paper proposes a feature-based image retrieval technique which uses a compound feature vector representing both of color and shape of an image. Color information for the feature vector is obtained using the algebraic moment of each pixel of an image based on the property of regional color distribution. Shape information for the feature vector is obtained using the Improved Moment Invariant(IMI) which reduces the quantity of computation and increases retrieval efficiency. In the preprocessing phase for extracting shape feature, we transform a color image into a gray image. Since we make use of the modified DCT algorithm, it is implemented easily and can extract contour in real time. As an experiment, we have compared our method with previous methods using a database consisting of 150 automobile images, and the results of the experiment have shown that our method has the better performance on retrieval effectiveness.