• Journal of the Korean Society of Radiology
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• v.18 no.5
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• pp.541-549
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• 2024

The various structures of artificial neural networks, such as convolutional neural networks (CNNs) and recurrent neural networks (RNNs), have been extensively studied and served as the backbone of numerous models. Among these, a transformer architecture has demonstrated its potential for natural language processing and become a subject of in-depth research. Currently, the techniques can be adapted for image processing through the modifications of its internal structure, leading to the development of Vision transformer (ViT) models. The ViTs have shown high accuracy and performance with large data-sets. This study aims to develop a ViT-based model for detecting pneumonia using chest X-ray images and quantitatively evaluate its performance. The various architectures of the ViT-based model were constructed by varying the number of encoder blocks, and different patch sizes were applied for network training. Also, the performance of the ViT-based model was compared to the CNN-based models, such as VGGNet, GoogLeNet, and ResNet. The results showed that the traninig efficiency and accuracy of the ViT-based model depended on the number of encoder blocks and the patch size, and the F1 scores of the ViT-based model ranged from 0.875 to 0.919. The training effeciency of the ViT-based model with a large patch size was superior to the CNN-based models, and the pneumonia detection accuracy of the ViT-based model was higher than that of the VGGNet. In conclusion, the ViT-based model can be potentially used for pneumonia detection using chest X-ray images, and the clinical availability of the ViT-based model would be improved by this study.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.10
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• pp.2481-2490
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• 2015

The issue of PHR is maintained on the server will be in the hospital. PHR information stored on the server, such as a patient's illness and treatment is very sensitive information. Therefore, patients should be guaranteed the protection of privacy. In addition, the PHR should be allowed to group access of it's approach. Therefore, in this paper the proposed group signature using hierarchical identity-based encryption schemes into can guarantee the PHR data privacy. The session key generated by group signature, it is use a tiered approach. The generated session keys safe PHR data transmission is possible. The proposed method is average 80% than the PKI encryption and ID-based encryption rather than average 50% the algorithm processing is more efficient

• Biomedical Science Letters
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• v.18 no.4
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• pp.399-405
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• 2012

The brain is the body's most organized and controlled organ, and it governs various psychological and mental functions. A brain abnormality could greatly affect one's physical and mental abilities, and consequently one's social life. Brain disorders can be broadly categorized into three main afflictions: stroke, brain tumor, and dementia. Among these, stroke is a common disease that occurs owing to a disorder in blood flow, and it is accompanied by a sudden loss of consciousness and motor paralysis. The main types of strokes are infarction and hemorrhage. The exact diagnosis and early treatment of an infarction are very important for the patient's prognosis and for the determination of the treatment direction. In this study, texture features were analyzed in order to develop a prototype auto-diagnostic system for infarction using computer auto-diagnostic software. The analysis results indicate that of the six parameters measured, the average brightness, average contrast, flatness, and uniformity show a high cognition rate whereas the degree of skewness and entropy show a low cognition rate. On the basis of these results, it was suggested that a digital CT image obtained using the computer auto-diagnostic software can be used to provide valuable information for general CT image auto-detection and diagnosis for pre-reading. This system is highly advantageous because it can achieve early diagnosis of the disease and it can be used as supplementary data in image reading. Further, it is expected to enable accurate medical image detection and reduced diagnostic time in final-reading.

• Imaging Science in Dentistry
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• v.40 no.3
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• pp.143-147
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• 2010

Purpose : This study was to investigate whether cervical vertebrae can be utilized in evaluating the growth of the maxilla. Materials and Methods : Fifty one male patients took lateral cephalometric radiographs once in every two years from the age of 8 till 14. Measured parameters were the concavity depth at the lower border of the third and fourth cervical vertebrae, and three analytical maxillary dimensions. Results : The analysis of the maxillary measurements and the concavity depth at the lower border of the cervical vertebrae in the lateral cephalometric radiographs showed that the measured parameters gradually increased as the patients aged. Moreover, while the parameters of the patients in age 8 and 10 did not show any correlation, those of the patients in age 12 and 14 definitely showed the correlations. Conclusions : Although certain correlations were seen in particular parameters, further researches and studies with various parameters and shorter age intervals are needed. The result of this study will help clinicians in making plans and evaluating the proposed treatment plans.

• Journal of the Korean Society of Radiology
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• v.13 no.5
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• pp.729-737
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• 2019

Fatty pancreas is an abnormal process of lipid deposition in cells, resulting in increased fat tissue and obesity. The result is a risk factor for cardiovascular and metabolic diseases. The aim of this study was to evaluate the usefulness of pancreatic fat as a predictor of cardiovascular disease and metabolic syndrome in pancreatic ultrasonography. In 407 patients who underwent a comprehensive screening at the W Health Care Center in Busan from September 2. 2018 to December 31, 2018, the degree of fat deposition in the pancreas was evaluated as the degree of mild, moderate. Data on non-obstructive atherosclerosis, BMI, hyperlipidemia, hypertension, and diabetes were collected to assess the association of pancreatic fat deposition with cardiovascular disease and metabolic syndrome. In addition, we tried to analyze the correlation between liver dysfunction and thyroid dysfunction as the degree of fat pancreas increased. We examined the relationship between six parameters including atherosclerosis, BMI, hyperlipidemia, hypertension, diabetes, liver dysfunction, and thyroid dysfunction among patients with fatty pancreas. We concluded that the carotid intima-media thickness of atherosclerosis, which is a risk factor of cardiovascular disease, is most closely related to fatty pancreas.

• Journal of the Korean Society of Radiology
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• v.12 no.3
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• pp.409-415
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• 2018

The development of smart devices has brought about significant changes in daily life and one of the most significant changes is the virtual reality zone. Virtual reality is a technology that creates the illusion that a 3D high-resolution image has already been created using a display device just like it does in itself. Unrealized subjects are forced to rely on audiovisual materials, resulting in a decline in the concentration of practices and the quality of classes. It used virtual reality to develop effective teaching materials for radiology students. In order to produce a video clip bridge using virtual reality, a radiology clinic was selected to conduct two exposures from July to September 2017. The video was produced taking into account the radiology and work flow chart and filming was carried out in two separate locations : in the computerized tomography unit and in the LINAC room. Prior to filming the scenario and the filming route were checked in advance to facilitate editing of the video. Modeling and mapping was performed in a PC environment using the Window XP operating system. Using two leading virtual reality camera Gopro Hero, CC pixels were produced using a 4K UHD, Adobe, followed by an 8 megapixel resolution of $3,840{\times}2,160/4,096{\times}2,160$. Total regeneration time was performed in about 5 minutes during the production of using virtual reality to prevent vomiting and dizziness. Currently developed virtual reality radiation and educational contents are being used to secure the market and extend the promotion process to be used by various institutions. The researchers will investigate the satisfaction level of radiation and educational contents using virtual reality and carry out supplementary tasks depending on the results.

• Journal of Sensor Science and Technology
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• v.17 no.3
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• pp.217-222
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• 2008

$BaCl_2$ crystals were grown by using the Czochralski method, and their scintillation properties were measured. The emission spectrum was located in the range of $370{\sim}450$ nm, peaking at about 400 nm. The fluorescence decay time was approximately 75.9 ns for 662 keV ${\gamma}$-rays excitation. The energy resolution was about 24.4 % for $^{137}Cs$ 662 keV ${\gamma}$-rays, and the ${\alpha}/{\beta}$ ratio to $\alpha$ particles from a $^{210}Po$ 5.4 MeV was about 0.25.

• Imaging Science in Dentistry
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• v.42 no.2
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• pp.71-75
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• 2012

Purpose : Dental trauma is frequently unpredictable. The initial assessment and urgent treatment are essential for dentists to save the patient's teeth. Mobile-phone-assisted teleconsultation and telediagnosis for dental trauma could be an aid when a dentist is not available. In the present in-vitro study, we evaluated the success rate and time to transfer images under various conditions. Materials and Methods : We analyzed the image quality of cameras built into mobile phones based on their resolution, autofocus, white-balance, and anti-movement functions. Results : The image quality of most built-in cameras was acceptable to perform the initial assessment, with the autofocus function being essential to obtain high-quality images. The transmission failure rate increased markedly when the image size exceeded 500 kB and the additional text messaging did not improve the success rate or the transmission time. Conclusion : Our optimal protocol could be useful for emergency programs running on the mobile phones.

• Parasites, Hosts and Diseases
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• v.46 no.3
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• pp.165-169
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• 2008

Microphallus species occur primarily as intestinal parasites of birds and mammals, and metacercariae of a new species belonging to this genus have been discovered from the crab, Macrophthalmus dilatatus, in the Republic of Korea. The metacercaria of this fluke was round with 2 thick walls, and the excysted one had mature genital organs. The adult flukes recovered from experimentally infected chicks had numerous intrauterine eggs, well-developed pars prostatica, widely bifurcating ceca, and prominent uterine bulge. After observing internal structures, it was concluded that this species is different from any other known Microphallus spp. Based on the morphology of metacercariae and adult flukes, we describe this specimen as a new species, Microphallus koreana n. sp.

• Imaging Science in Dentistry
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• v.48 no.4
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• pp.295-300
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• 2018

This report presents a clinical case of trauma due to assault with a knife, and describes the importance of using the correct imaging modality in cases of facial penetrating trauma involving the superficial and deep anatomical planes. Penetrating wounds in the maxillofacial region are rare and poorly reported, but can result in serious complications that are difficult to resolve and may compromise the patient's quality of life, especially when large blood vessels or other vital structures are involved. Thus, it is essential to determine the extent of the affected blood vessels and the proximity of the retained object to the anatomical structures. In this case, digital subtraction angiography was the imaging modality chosen. The use of appropriate imaging examinations allows a proper map of the surgical field, reducing the chances of vascular damage during the surgical procedure.