• The Journal of the Korea Contents Association
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• v.11 no.4
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• pp.244-252
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• 2011

This study was to estimate the radiation dose associated with 64-slice multidetector CT(MDCT) in clinical practice and quantify the potential cancer risk associated with these examinations. Lifetime attributable risks(LAR) were estimated with models developed in the national Academies' Biological Effects of Ionizing Radiation VII report. Mean effective dose were 1.48mSv in Brain axial scan, 7.66mSv in chest routine contrast, 12.17mSv in coronary angiogram, 24.52mSv in Dynamic abdomen scan. LAR estimates for brain routine varied from 1 in 7463 for man to 1 in 4926 for women. In chest routine with contrast, LAR varied from 1 in 1449 for men to 1 in 952. LAR of Abdomen dynamic CT varied from 1 in 453 for men to 1 in 298 for women. So, 64-slice MDCT scan is associated with non-negligible LAR of cancer. Doses can be reduced by careful attention to scanning protocol.

• Journal of Radiation Protection and Research
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• v.39 no.4
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• pp.206-212
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• 2014

We report here on the results of evaluating the radiation doses using chest computed tomography (CT) for patients with pneumoconiosis complication. For the first time, we visited the 17 MIPs to evaluate the dose-length product (DLP, $mGy{\cdot}cm$), CT unit, and protocols of scanning and image reconstruction those is routinely used for treating patients with pneumoconiosis who have complication. All statistical analysis was performed using the Statistical Program for Social Sciences (SPSS ver. 19.0, Chicago, IL, USA). Mean of total DLP was $727.7mGy{\cdot}cm$, ranging from 272.0 to $1228.7mGy{\cdot}cm$. DLP from obtaining parenchymal lung images was significantly reduced than that from obtaining total lung images (555.9 vs. 707.2, p<0.001). Third quartile of total and pre-scanning DLP was 1036.1 and $504.1mGy{\cdot}cm$, respectively. Chest CT radiation doses for patients with pneumoconiosis complication are similar with korean diagnostic reference level as well as international guidelines.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.7-11
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• 2012

Purpose : The effect of concomitant use of $^{18}F$-FDG and intravenous contrast agent (CA) on dual-energy X-ray absorptiometry (DXA), was rarely reported. We had investigated these potentially confounding effects. Materials and Methods : Twenty-two patients had undergone DXA before and immediately after $^{18}F$-FDG PET/CT scans. Two DXA and 1 PET/CT scans had performed within one-day. $^{18}F$-FDG PET/CT scans had been performed with CA in 17 patients and without CA in 5 patients. Whole body bone mineral content (BMC), whole body bone mineral density (BMD), total fat mass (TFM), and lean body mass (LBM) were measured by DXA scanner before and after the $^{18}F$-FDG PET/CT scans. Results : BMC, BMD, TFM and LBM had significantly affected by $^{18}F$-FDG PET/CT with CA (BMC, +13.7%, from $2061.3{\pm}393.7$ to $2343.4{\pm}373.3$; BMD, +9.3%, from $1.07{\pm}0.09$ to $1.17{\pm}0.08$; TFM, -34.1%, from $17052.1{\pm}4049.9$ to $11237.1{\pm}2990.3$; LBM, +13.6%, from $45834.5{\pm}5662.1$ to $52094.0{\pm}6335.4$). However, $^{18}F$-FDG PET/CT without CA had no effect on the measurement of DXA (BMC, +2.4%, from $2197.7{\pm}391.6$ to $2251.5{\pm}380.9$; BMD, +1.8%, from $1.13{\pm}0.09$ to $1.15{\pm}0.07$; TFM, -6.8%, from $14585.6{\pm}3455.9$ to $13591.3{\pm}4351.4$; LBM, +2.2%, from $47360.5{\pm}8381.8$ to $48441.1{\pm}8488.1$). Conclusion : The measurements of DXA are affected by using CA. However, DXA scans might be unaffected by the presence of $^{18}F$-FDG administered for PET/CT.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.9
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• pp.137-142
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• 2016

When injecting intravenously of CT inspection, the effusion of the contrast meium can induce the tissue damage with the blood vessel outside. We detect extravasation which is generated in the course where we inject the contrast medium into the blood vessel. And we use the bolus tracking system for the detection of that. By using MPR and VR images, moreover we detected the extravasation in order to prevent the tissue damage. In order to detect the effusion of the contrast medium, we used 16-MDCT and 64-MDCT. Three dimensional images about the outflow of the blood vessel can provide the treatment information which is important in the patient treatment. Moreover we applied the image processing technique in order to improve sharpness between contrast media and organization. And sharpness and contrast was improved.

• Journal of the Korean Society of Radiology
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• v.5 no.2
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• pp.51-58
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• 2011

This research compared and analyzed the heart rate of the patient in which the LVEF value is 40% less than and normal patient. When as for LVEF 40% or less becomes to each heart rate and LVEF in a relation, we can know that the time to reach 100HU hangs long. Therefore, in patients, that is 40% less than, when setting up the Premonitoring delay, we could know to could give 5 primary solid phrases. It is seen that subsequently an addition injected 40cc as to Saline, to all patients by 4cc/sec speeds after injecting the capacity of Scan time ${\times}$ 4cc + 30cc with 4cc/sec speeds. And HR excludes 80 or greater in 40% less than, the contrast agent shows the large-scale difference. In addition, in 40% less than, it could predict that the time difference was big and the contrast agent was already out in the Left ventricle Wash- when the contrast agent reached 100HU and Scan was started There is a wide difference between under 40% LVEF and normal. when starting scan from low LVEF patients. So, Injection contrast media protocol Should be determined to CCTA. And then In case of low LVEF is recommended to more low Pitch than routine Pitch because we should reduce scan failed in accordance with low LVEF.

• Proceedings of the Korean Society of Radiological Science
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• 1994.10a
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• pp.106.1-106.1
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• 1994

• Proceedings of the Korea Contents Association Conference
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• 2015.05a
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• pp.173-174
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• 2015

간에서 발생하는 악성종양과 양성종양의 대표적 질환 으로는 간세포암(Hepatocelluar carci- noma, HCC)과 간혈관종(Hepatic hemangioma, HH)이다. CT검사를 이용한 진단에 있어서 두 질환은 시간변화에 따른 조영증강양상 차이가 나타난다. Liver 3-phase computed tomography검사를 시행하여 시간별 조영증강 양상을 알아보았다. 본 연구는 조영제 주입전, 동맥기(35sec), 문맥기(70sec), 지연기(180sec)에 대한 Enhan -cement Pattern 변화와 HU(Hounsfield unit)값 변화, pixel값 변화의 관찰로서 검증하였다. 실험결과 HU를 사용한 방법에서 의미있게 구분되었고 임상적용 시 판독에 도움을 줄 것으로 생각한다.

• Journal of the Korea Convergence Society
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• v.6 no.5
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• pp.287-294
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• 2015

The purpose of this study, was Let's examine the exposure dose at the time of cerebral blood flow CT scan of acute ischemic stroke patients. In particular, long-term high doses of radiation sensitive organs and we Measured using phantom and a glass dosimeter. Apply the existing protocol suggested by the manufacturer (fixed time delay technique) and the proposed new convergence protocol (bolus tracking technique), reporting to measure the dose, dose reduction was to prepare the way. Results up to 39.8% as compared to the existing protocols in a new suggested convergence protocol, a minimum of 5.8% was long-term dose is reduced. Test dose of $CDTI_{vol}$ and DLP values decreased 25%, respectively, were measured at less than recommended dose. Try checking the protocol set out in the existing based on the analysis result of the above, by applying the proposed new convergence protocol by reducing the dose would have to contribute to improved public health. It is believed to be research continues to find the optimum protocol in the other tests.

• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.423-431
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• 2023

The purpose of this study is to analyze the factors affecting the classification of the severity of contrast media side effects based on the patient's body information using artificial intelligence techniques to be used as basic data to reduce the degree of contrast medium side effects. The data used in this study were 606 examiners who had no contrast medium side effects in the past history survey among 1,235 cases of contrast medium side effects among 58,000 CT scans performed at a general hospital in Seoul. The total data is 606, of which 70% was used as a training set and the remaining 30% was used as a test set for validation. Age, BMI(Body Mass Index), GFR(Glomerular Filtration Rate), BUN(Blood Urea Nitrogen), GGT(Gamma Glutamyl Transgerase), AST(Aspartate Amino Transferase,), and ALT(Alanine Amiono Transferase) features were used as independent variables, and contrast media severity was used as a target variable. AUC(Area under curve), CA(Classification Accuracy), F1, Precision, and Recall were identified through AdaBoost, Tree, Neural network, SVM, and Random foest algorithm. AdaBoost and Random Forest show the highest evaluation index in the classification prediction algorithm. The largest factors in the predictions of all models were GFR, BMI, and GGT. It was found that the difference in the amount of contrast media injected according to renal filtration function and obesity, and the presence or absence of metabolic syndrome affected the severity of contrast medium side effects.

• Journal of Digital Convergence
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• v.13 no.9
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• pp.431-437
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• 2015

This convergence study analyzed the effectiveness of contrast agent reduction by normal saline solution dilution in the computed tomography of arteries of lower limb. 48 patients of 125 cc contrast agent and 30 patients of the same amount divided at a ratio of 7:3 for the contrast agent and normal saline solution were studied. The average attenuation coefficient(HU) and signal to noise ratio(SNR) of abdominal aorta, femoral artery, popliteal artery and posterior tibial artery at each image were evaluated quantitatively and the four criteria in the five point scale was conducted qualitatively by two radiologists and four radiological technologists. In the quantitative evaluation, both HU and SNR had high average score before dilation but there were no statistical significance by independent t-test(p>0.05). In the qualitative evaluation, there were a little differences in the average scores between 4.86~4.77 of original contrast agent and 4.83~4.67 of dilated contrast agent but there were no statistical significance(p>0.05). In the computed tomography of arteries of lower limb, the dilated contrast agent doesn't influence image quality and reduces overall contrast agent and lowers iodine content per unit of molecular therefore will contribute to decrease side effect of contrast agent.