• Journal of the Korean Society of Radiology
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• v.17 no.1
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• pp.123-129
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• 2023

The purpose of this study was to analyze differences in imaging quality and dose difference between intra-venous (IV) and intra-arterial (IA) liver dynamic computed tomography (CT). Herein, retrospective, blinded analysis was conducted to analyze signal-to-noise and contrast-to-noise ratios in cases of patients who underwent IV or IA liver dynamic CT for transarterial chemoembolization (TACE), an interventional procedure for hepatocellular carcinoma. The dose length product (DLP) value stored in Picture Archive and Communication System (PACS) was used to calculate the effective dose and thereby compare differences in the dose between the two methods. The mean liver and spleen signal to noise ratio (SNR) was greater in IV-liver dynamic CT than in IA-liver dynamic CT; however, contrast to noise ratio (CNR) was higher in IA-liver dynamic CT than in IV-liver dynamic CT. However, there were no differences in DLP and effective dose between the two methods. In conclusion, our findings showed that IA-liver dynamic CT showed a similar effective dose and superior CNR compared with IV-liver dynamic CT. Further studies must analyze 3D angiography CT of the hepatic artery to clearly distinguish the feeding artery, which is the essential step in interventional procedures for hepatocellular carcinoma.

• Journal of the Korean Society of Radiology
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• v.12 no.2
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• pp.271-275
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• 2018

It is possible to do not use the Image Plate for a long time in the clinic. for the acquisition of reliable images the decommissioning process is very important. In this study, we would like to look at complex noises that may occur during Image Plate use depending on the frequency and time of day. first, we got the image from computer radiography. second, We calculate the noise changes using Peak Signal to Noise Ratio(PSNR) and Noise Power Spectrum(NPS). finally, we suggest that remove the noise from the IP for more than 4 hours. and It turned out to be better to remove the noise more than once. this study will be a quantitative reference for Image Plate management and use in the clinical trial.

• Journal of Veterinary Clinics
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• v.30 no.5
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• pp.390-393
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• 2013

This case study describes the imaging features of radiography and computed tomography (CT) in four small breed dogs with lung lobe torsion. The medical records, thoracic radiographs and CT images of four dogs with confirmed lung lobe torsion were retrospectively reviewed. Pleural effusion and increased lobar opacity/density were seen on all CT and thoracic radiography in all four dogs. CT revealed narrowed/collapsed bronchus in all four dogs, while this was only appreciated on one thoracic radiography. The vesicular emphysema pattern was seen on four CT but only on three radiographic examinations. The specific findings of lung lobe torsion were vesicular emphysema and a narrowed/collapsed bronchus. These findings were more easily recognized on CT than with thoracic radiographs.

• Journal of radiological science and technology
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• v.28 no.2
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• pp.123-128
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• 2005

It is necessary to obtain images of high diagnosis worth based on ability and skill of radiological technologist in case of acquisition of medical radiologaphy information. In addition, we need the various kinds of education considering individual radiological technologist variation and the organization of clinical education according to the large amount of learning and more expensive knowledge of radiology. In this paper, we implement CAI system for cervical vertebrae fracture radiograph with multimedia authoring tools on web environments. The CAI system can train a new radiological technologist and study a lot of radiological technologist on the cervical vertebrae fracture radiography acquisition based on more objective and systematical data in radiography room. The proposed CAI system is also expected as a useful program which can help to cure patients based on accurate diagnosis as well as obtain radiography more quickly using a technology of radiography acquisition for cervical vertebrae fracture.

• Journal of Veterinary Clinics
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• v.30 no.5
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• pp.366-370
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• 2013

A 7-month-old Pomeranian presented with non-weight bearing lameness on the right pelvic limb. Physical examination revealed pain on extension of the right hip joint, and serum chemistry results showed an increased concentration of creatine kinase. Radiographic findings at admission included a weak radiolucent line on the right femoral head and widening of the right hip joint space, and mild displacement of the right capital femoral epiphysis was additionally identified on day 14. Computed tomography (CT) showed a decreased Hounsfield Unit measurement and a fracture line on the right femoral head. Early stage Legg-Calve-Perthes disease (LCPD) was diagnosed and femoral head and neck ostectomy was performed on the right femur. A fracture fissure and osteophytes at the epiphyseal plate of the femoral head were identified surgically. Necrosis in the femoral metaphysis and epiphysis was observed histologically. This case report describes the radiography, CT images, and surgical and histological findings in a dog with early stage LCPD.

• Journal of the Korean Society of Radiology
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• v.15 no.3
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• pp.293-299
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• 2021

In order to reduce the irresistible radiation exposure of patients who perform periodic examinations using a CT among various scan parameters a method to reduce patient dose was investigated through changes in the tube voltage close to X-ray penetrating power. As a result of the experiment 100 kVp was applied instead of 120 kVp which is commonly used in clinical practice and CTDI decreased by about 41% during scan. In addition the degree of change in image quality was measured as 1046.1±3.7 HU for CT value and 71.4±7.9 for Pixel value and statistical analysis showed no significant difference (0.05

• Journal of Digital Convergence
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• v.16 no.12
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• pp.441-447
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• 2018

This study aims to develop digital techniques that enable repeated practice of dental radiography using augmented reality technology. A three-dimensional object was fabricated by superimposing a photograph of an adult model and a computed tomography image of a manikin phantom. The system was structured using 106 radiographs such that one of these saved radiographs is opened when the user attempts to take a radiograph on a mobile device. This system enabled users to repeatedly practice at the pre-clinical stage without exposure to radiation. We attempt to contribute to enhancing dental hygienists' competency in dental radiography using these techniques. However, a system that enables the user to actually take a radiograph based on face recognition would be more useful in terms of practice, so additional studies are needed on the topic.

• Journal of the Korean Society of Radiology
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• v.11 no.6
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• pp.453-458
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• 2017

Computed Tomography (CT) provides information on the Diagnostic Reference Level Computed Tomography Dose Index (CTDI) and Dose Length Product (DLP) for accurate diagnosis of patients. However, it does not provide a dose change according to the table height for the diagnostic reference level provided by the CT equipment. The purpose of this study was to evaluate the image and dose according to the table height change using phantom (PMMA: Polymethyl Methacrylate) in order to find the optimal image and the minimum dose during computed tomography examination. When examining using a 32 cm PMMA phantom with the same thickness as the abdomen of an adult, there was little change in dose with table height. However, the noise evaluation of the image caused a high fluctuation of noise depending on the table height. and in the case of the 16 cm PMMA phantom, the change of the noise was small, but the dose change was about 30%. In conclusion, the location of the patient and the center of the detector are important during computed tomography (CT) examinations. In addition, table height setting is considered to be important for examinations with optimized image and minimum dose.

• Progress in Medical Physics
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• v.9 no.1
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• pp.1-9
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• 1998

In order to provide complementary image data, CT(computed tomography), MR(magnetic resonance) and angiography have been used in the field of Stereotactic Radiosurgery(SRS) and neurosurgery. The aim of this work is to develop 3-D stereotactic localization system in order to determine the precise shape, size and location of the lesion in the brain in the field of Stereotactic Radiosurgery(SRS) and neurosurgery using multi-image modality and multi purpose QA phantom. In order to obtain accurate position of a target, Hitchcoke stereotactic frame and CT/angiography localizers were rigidly attached to the phantom with nine targets dispersed in 3-D space. The algorithms to obtain a 3-D stereotactic coordinates of the target have been developed using the images of the geometrical phantom which were taken by CT/angiography. Positions of targets computed by our algorithms were compared to the absolute position assigned in the phantom. Outlines of targets on each CT image were superimposed each other on angiography images. A spatial mean distance errors were 1.02${\pm}$0.17mm for CT with a 512${\times}$512 matrix and 2mm slice thickness, 0.41${\pm}$0.05mm for angiogra- phy localization. The resulting accuracy in the target localization suggests that the developed system has enough Qualification for Stereotactic Radiosurgery (SRS).

• 대한방사선방어학회:학술대회논문집
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• 2011.04a
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• pp.132-133
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• 2011