• Korean Journal of Radiology
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• v.21 no.7
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• pp.919-924
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• 2020

Objective: The current study reported a case series to illustrate the early computed tomography (CT) findings of coronavirus disease 2019 (COVID-19) in pediatric patients. Materials and Methods: All pediatric patients who were diagnosed with COVID-19 and who underwent CT scan in Zhongnan Hospital of Wuhan University from January 20, 2020 to February 28, 2020 were included in the current study. Data on clinical and CT features were collected and analyzed. Results: Four children were included in the current study. All of them were asymptomatic throughout the disease course (ranging from 7 days to 15 days), and none of them showed abnormalities in blood cell counts. Familial cluster was the main transmission pattern. Thin-section CT revealed abnormalities in three patients, and one patient did not present with any abnormal CT findings. Unilateral lung involvement was observed in two patients, and one patient showed bilateral lung involvement. In total, five small lesions were identified, including ground-glass opacity (n = 4) and consolidation (n = 1). All lesions had ill-defined margins with peripheral distribution and predilection of lower lobe. Conclusion: Small patches of ground-glass opacity with subpleural distribution and unilateral lung involvement were common findings on CT scans of pediatric patients in the early stage of the disease.

• The Korean Journal of Nuclear Medicine Technology
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• v.22 no.1
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• pp.35-42
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• 2018

Purpose Standardized uptake value(SUV) has been widely used as a quantitative metric of uptake in PET/CT for diagnosis of malignant tumors and evaluation of tumor therapy response. However, the SUV depends on various factor including PET/CT scanner specifications and reconstruction parameter. The purpose of this study is to validate a EQ PET to evaluate SUV across different PET/CT systems. Materials and Methods First, NEMA IEC body phantom data were used to calculate the EQ filter for OSEM3D with PSF and TOF reconstruction from three different PET/CT systems in order to obtain EARL compliant recovery coefficients of each spheres. The Biograph true point 40 PET/CT images were reconstructed with a OSEM3D+PSF reconstruction, images of the Biograph mCT 40 and Biograph mCT 64 PET/CT scanners were reconstructed with a OSEM3D+PSF, OSEM3D+TOF, OSEM3D+PSF+TOF. Post reconstructions, the proprietary EQ filter was applied to the reconstruction data. Recovery coefficient can be estimated by ratio of measured to true activity concentration for spheres of different volume and coefficient variability(CV) value of RC for each sphere was compared. For clinical study, we compared SUVmax applying different reconstruction algorithms in FDG PET images of 61 patients with lung cancer using Biograph mCT 40 PET/CT scanner. Results For the phantom studied, the mean values of CV for OSEM3D, OSEM3D+PSF, OSEM3D+TOF and OSEM3D+PSF+TOF reconstructions were 0.05, 0.04, 0.04 and 0.03 respectively for RC. Application of the proprietary EQ filter, the mean values of CV for OSEM3D, OSEM3D+PSF, OSEM3D+TOF and OSEM3D+PSF+TOF reconstructions were 0.04, 0.03, 0.03 and 0.02 respectively for RC. Clinical study, there were no statistical significance of the difference applying EQ PET on SUVmax of 61 patients FDG PET image. (p=1.000) Conclusion This study indicates that CV values of RC in phantom were decreased after applying EQ PET for different PET/CT system and The EQ PET reduced reconstruction dependent variation in SUVs for 61 lung cancer patients, Therefore, EQ PET will be expected to provide accurate quantification when the patient is scanned on different PET/CT system.

• Journal of the Korean Society of Earth Science Education
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• v.10 no.2
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• pp.140-160
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• 2017

The purpose of this study was to develop computational thinking (CT) analysis tool that can be used to analyze CT practices; first, by defining what CT practices are, and then, by identifying which components of CT are reflected in STEAM classes. Exploring various kinds of CT practices, which can be identified while applying the proposed CT analysis tool for exemplary STEAM classes, is another goal of this study. Firstly, to answer the question of "What is CT in science education" and thereby to develop the proposed CT practice analysis tool, three types of published documents about CT definition as the main data in this study have been considered. In the first "analysis tool development" part of this study, the following five elements have been identified as the main components of CT analysis tool as follows; (1) connecting open problems with computing, (2) using tools or computers to develop computing artifact, (3) abstraction process, (4) analyzing and evaluating computing process and artifact, and (5) communicating and cooperating. Based on the understandings that there is a consistent flow among the five components due to their interactions, a flow chart of CT practice has also been developed. In the second part of this study, which is an implementation study, the proposed CT practice analysis tool has been applied in one exemplary STEAM program. To select the candidate STEAM program, four selection criteria have been identified. Then, the proposed CT practice analysis tool has been applied for the selected STEAM program to determine the degree of CT practice reflected in the program and furthermore, to suggest a way of improving the proposed CT analysis tool if it shows some weak points. Through the findings of this study, we suggest that the actual definition of computational thinking will be helpful to converge Technology and Engineering to STEAM education and a strong complement to reinforce STEAM education.

• Journal of radiological science and technology
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• v.37 no.4
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• pp.315-322
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• 2014

This study demonstrates holding condition of CT by medical institution classification and by season, and examination fee in Korea currently to quantitatively understand frequency of examination region by change of CT equipment, domestic growing trend and change of distribution and using rate. Recent 10 years of CT holding condition by medical institution classification (Tertiary hospital, General hospital, Hospital, Clinic, Dental hospital, Dental clinic, Hospitalized health center) and by year (2003-2012), and CT examination fee of distribution of medical institution by year is surveyed. The holding ratio of Tertiary hospital level and General hospital level is 32.7% in 2003 and 33.0% in 2012. Whereas, Hospital and Clinic level is 74.2% in 2003 and 66.8% in 2012, which takes approximately 70%. Based on data in 2012, it is 82.2% of total examination fee in Tertiary hospital and General hospital, while 17.5% in hospital and clinic. CT holding rate of Hospital level is increasing, while Clinic level is decreasing. Approximately 80% of CT examination fee is claimed by Tertiary hospital and General hospital. Therefore, there is a significant correlation between CT holding condition of medical institution classification and examination fee. Particularly, correlation between CT holding number of Tertiary hospital and examination fee is significant (p<.001). The more CT holding number, the higher the amount claimed examination fee.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.5
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• pp.331-337
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• 2023

In this paper, we propose a deep learning model to detect lumbar 3 (L3) CT images to determine the occurrence and degree of sarcopenia. In addition, we would like to propose an optimization technique that uses oversampling ratio and class weight as design parameters to address the problem of performance degradation due to data imbalance between L3 level and non-L3 level portions of CT data. In order to train and test the model, a total of 150 whole-body CT images of 104 prostate cancer patients and 46 bladder cancer patients who visited Gangneung Asan Medical Center were used. The deep learning model used ResNet50, and the design parameters of the optimization technique were selected as six types of model hyperparameters, data augmentation ratio, and class weight. It was confirmed that the proposed optimization-based L3 level extraction model reduced the median L3 error by about 1.0 slices compared to the control model (a model that optimized only 5 types of hyperparameters). Through the results of this study, accurate L3 slice detection was possible, and additionally, we were able to present the possibility of effectively solving the data imbalance problem through oversampling through data augmentation and class weight adjustment.

• The Korean Journal of Nuclear Medicine Technology
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• v.12 no.3
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• pp.235-240
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• 2008

Purpose: At the beginning of PET/CT, Computed Tomography was mainly used only for Attenuation Correction (AC), but as the performance of the CT have been increase, it could give improved diagnostic information with Contrast Media. But it was controversial that Contrast Media could affect AC on PET/CT scan. Some submitted thesis' show that Contrast Media could overestimate when it is for AC data processing. On the contrary, the opinion that Contrast Media could be possible to affect the alteration of SUV because of the overestimated AC. But it does not have a definite effect on the diagnosis. Thus, the affection of Contrast Media on AC was investigated in this study. Materials and Methods: Patient inclusion criteria required a history of a malignancy and performance of an integrated PET/CT scan and contrast- enhanced CT scan within a 1-day period. Thirty oncologic patients who had PET/CT scan from December 2007 to June 2008 underwent staging evaluation and met these criteria. All patients fasted for at least 6 hr before the IV injection of approximately 5.6 MBq/kg (0.15 mCi/kg) of $^{18}F$-FDG and were scanned about 60 min after injection. All patients had a whole body PET/CT performed without IV contrast media followed by a contrast-enhanced CT on the Discovery STe PET/CT scanner. CT data were used for AC and PET images came out after AC. The ROIs drew and measured SUV. A paired t-test of these results was performed to assess the significance of the difference between the SUV obtained from the two attenuation corrected PET images. Results: The mean and maximum Standardized Uptake Values (SUV) for different regions averaged over all Patients. Comparing before using Contrast Media and after using, Most of ROIs have the increased SUV when it did Contrast Enhanced CT compare to Non-Contrast enhanced CT. All regions have increased SUV and also their p value was under 0.05 except the mean SUV of the Heart region. Conclusion: In this regard, the effect on SUV measurements that occurs when a contrast-enhanced CT is used for attenuation correction could have significant clinical ramifications. But some submitted thesis insisted that the percentage change in SUV that can determine or modify clinical management of oncology patients is small. Because there was not much difference that could be discovered by interpreter. But obviously the numerical change was occurred and on the stage finding primary region, small change would be base line, such as the region of liver which has greater change than the other regions needs more attention.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.5
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• pp.409-415
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• 2016

Recently several techniques for disaster prevention based on IoT(Internet of Things) are being developed. In this paper, a new smart pattern classification method for electric loads is proposed. CT(Current Transformer) data are extracted from electric loads, and then the sampled CT data are converted using FFT and MFCC. FFT and FMCC data are used for the input data of neural networks. Experiments were conducted using FFT and MFCC data for 7 kinds of electric loads. Experiments results indicate the superiority of MFCC in comparison to FFT.

• The Journal of the Korea Contents Association
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• v.17 no.10
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• pp.567-575
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• 2017

In this study, when diagnosis pancreatic cancer by dual time point PET/CT, we propose SUVm 2.52 as the threshold value for performing the dual time point PET/CT exam. The hypothesis of normal distribution was adopted through data conversion of 60 pancreatic diseases. The proposed SUVm2.52 boundary value showed a significance level that could be applied to both 120 and 180 minutes of delay time scan for pancreatic cancer determination (p<0.05). C-value variation shows that delay time 2 hour test is more useful than delay time 3 hour test. When the SUVm 2.52 is set to the boundary value and the double-time point PET/CT exam is performed, the probability of distinguishing cancer from inflammation in the delayed image is 95%. When the delayed test is performed with the proposed boundary value SUVm 2.52, Compared with general PET / CT scans, it is thought that it may be helpful to distinguish pancreatic cancer.

• The Journal of Korean Society for Radiation Therapy
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• v.2 no.1
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• pp.81-85
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• 1987

It has been evident since 1972 that computed tomography(CT) can play an important role in treatment and managment of the cancer patients as four steps; diagnosis, satging Treatment and follow-up. In this paper, we intended to investigate the availability of CT scan and treatment planning computer in 700 cancer patients who have undergone radiation therapy at the division of radiation therapy, Kangnam St. Mary's Hospital, Catholic Medical College between Mar. 1983 and Dec. 1985. The result were as follow; 1. Of 700 irradiated cancer patients, 342 patients ($48.9\%$) were performed CT scan prior to radiation therapy. 2. The distribution of lesions in 342 patients having CT scans was like this; CNS (83 of 104 patients, $79.8\%$), abdomen (44 of 76 patients, $57.9\%$), pelvis (100 of 188 patients, $53.2\%$) etc. in order. 3. The treatment planning computer were used in 280 cancer patients ($40\%$). 4. Of the 280 cancer patients using treatment planning computer, 167 patients ($59.6\%$) applied diagnostic CT scan and remaining 113 patients ($40.4\%$) were made body contour to be used for radiation therapy planning by the treatment planning computer. Authors also made some magnification devices used for small multiformat CT images to magnify into life size, consisting of overhead projector (3M) I.V. stand and mirror. These enabled us to make less errors in tracing the small-sized CT images during input of the anatomical data into the treatment planning computer.

• Korean Journal of Digital Imaging in Medicine
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• v.10 no.2
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• pp.17-22
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• 2008

It is to improve customer satisfaction measurement and CT Scan process without delay of examination time when is using Scan positioning time(Planning time) that time is happened always between research reactor CT examination to increase fear and examination satisfaction by the customer's comprehension tribe which get the latest contrast enhancement CT examination. Needs and interests that customer wants to compose visual and auditory Contents to be played to Scan positioning time did questionnaire about curiosity later before CT examination to 600 people for October - November 2 months of 2006 to customer whole that get CT examination on source. Data getting through questionnaire investigated examination comprehension and satisfaction through questionnaire after experiment Scan Positioning to 500 coming to help customers to be source CT examination for 3 months February December - 2007 year in 2006 manufacturing Voice and Visual announce media for reference. To customer who interest degree appeared, and answers preparatory audit from preparatory audit about curiosity of CT examination customer to order of examination time required(43%), contrast media side effect(26%), examination region(20%), breath(10%), etc..(1.5%) audio-visual materials in questionnaire that attain after do reclamation among examination age, sex, reception type of irrelatively in 91% of target increase of hailing degree and examination satisfaction appear. Searched that customer hailing and satisfaction are increased greatly when use of audio-visual materials in satisfaction result that use CT Positioning delay time. In experiment process, It took lacking part by method that use hearing in case of do not use sight as is unavoidable in subject position or old age. Through this, audio-visual materials could analogize that it is more useful method that use sight and hearing at the same time.