• Journal of the Korean Society of Radiology
• /
• v.17 no.3
• /
• pp.417-422
• /
• 2023

In this study, normal saline was diluted with the contrast medium at a certain ratio for the purpose of reducing the image quality poor and side effects caused by the contrast medium during CT examination. At this time, by finding the energy level of DECT that can compensate for the decrease in contrast of the image according to the degree of dilution, the usefulness of applying DECT for compensating the difference in image contrast was investigated through comparative analysis by applying SNR, CNR, and SSIM. As a result, when a dilution ratio of 4 (contrast medium): 6 (normal saline) and the energy level of DECT of 65 keV were applied, the contrast difference was the most similar to that when using the undiluted contrast medium. At this time, SNR was 813.71 ± 37.6, CNR was the highest at 921.87 ± 17.1, and SSIM index was measured at 0.851, which is the most similar to 1. The results of this study are meaningful in providing basic information for finding the appropriate dilution rate and energy level for each examination site through future clinical studies. It is believed that it can be reduced.

• Journal of The Korean Radiological Technologist Association
• /
• v.25 no.1
• /
• pp.70.2-71
• /
• 1999

• Journal of The Institute of Information and Telecommunication Facilities Engineering
• /
• v.1 no.1
• /
• pp.86-95
• /
• 2002

• Proceedings of the Korean Institute of Landscape Architecture Conference
• /
• 2011.10a
• /
• pp.94-98
• /
• 2011

• Proceedings of the Korean Institute of Landscape Architecture Conference
• /
• 2018.11a
• /
• pp.120-122
• /
• 2018

• Journal of the Korea Society of Computer and Information
• /
• v.7 no.1
• /
• pp.33-47
• /
• 2002

• Journal of the Korean Society of Radiology
• /
• v.17 no.6
• /
• pp.827-833
• /
• 2023

CT(Computed Tomography) contrast agents are commonly used in general hospitals and university hospitals when taking radiographic examinations. The CT contrast medium contains a mixture of a substance called "Iodine", which absorbs radiation energy and makes it appear white in the CT image, further improving the image quality. In addition, the CT contrast agent, which moves like blood in the blood vessels, clearly differentiates it from muscle and water, so CT contrast agents are widely used in hospitals. These CT contrast agents absorb X-rays, but in order to absorb X-rays, they must have a high density or a high radiation absorption coefficient. Since the CT contrast agent is injected into the blood vessels, if the density is high, the blood vessels are strained and the patient is in shock. For this reason, it is necessary to match the density similar to that of water and always pay attention to side effects. In addition, the amount of CT contrast medium is adjusted according to the patient's body shape, and the remaining contrast medium is discarded. However, This study tried to find out the idea of recycling it as a radiation shielding material. Since the CT contrast medium has a high radiation absorption coefficient at a density similar to that of water, the amount to absorb radiation is adjusted, the amount of contrast medium and the amount of water are adjusted, and the amount of radiation absorbed is determined by mixing with water. In addition, a study was conducted to find out the result of the difference in radiation absorption in various ways by comparing the radiation quality coefficient and absorption coefficient with other substances or materials in an environmentally friendly method harmless to the human body by mixing CT contrast medium and water.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.2
• /
• pp.786-792
• /
• 2013

In this study was explored minimize side effects due to the additional injection of contrast medium and maintaining a high resolution imaging applied to the inspection and analysis of the contrast medium that affect the peak time biomechanics factors. Included 48 patients using the test bolus method, after measuring a patient's biomechanics factors of inspection before and during the test, correlation between contrast medium peak time and learn, matches the regression equation calculated and measured contrast medium peak time was assessed by the Bland Altman plot. Research result, inspections of SBP, HR contrast medium peak time and a significant negative correlation was, step 1, every increase, the contrast medium peak time significantly to -0.018 and -0.159 decreased, a fairly high concordance no difference between the two method. In conclusion, the regression equation using the existing methods, while maintaining excellent image quality that contrast medium is reduced to a patient, it can conclude that the alternative to the existing methods.

• Journal of Yeungnam Medical Science
• /
• v.25 no.2
• /
• pp.102-107
• /
• 2008

Background : Malignant pulmonary nodules account for 30 to 40 percent of all solitary pulmonary nodules (SPNs). Therefore, characterization of SPNs is very important for treatment. Recently, dynamic CT has been widely used for tissue characterization and formation of differential diagnoses. The purpose of this study was to evaluate the ability of dynamic CT to formulate the differential diagnosis of SPNs. Materials and Methods : Nineteen patients with SPNs underwent dynamic CT (unenhanced scans, followed by a series of images at 20, 40, 60, 80, 100, 120, 140, 160, and 180 sec after intravenous injection of contrast medium). Diagnosis of SPN was performed based on pathologic findings in needle biopsy samples. Peak enhancement, net enhancement, slope of enhancement, and maximum relative enhancement ratio of the SPN were measured on dynamic CT, and Levene's test was performed to assess benignancy and malignancy. Results : Twelve SPNs were confirmed to have malignant pathology. There were no significant differences between benign and malignant nodules with respect to peak enhancement (p=0.787), net enhancement (p=0.135), or slope of enhancement (p=0.698). The maximal enhancement ratio was increased in malignancy compared to benignancy, but the difference was not statistically significant (p=0.094). Conclusion : In our study, the hemodynamic characteristics of dynamic CT were not significantly different between benign and malignant nodules. Therefore, long-term studies of larger patient samples are required to confirm our findings.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2018.07a
• /
• pp.301-302
• /
• 2018

본 논문에서는 대한민국 공항 관제권 구역과 비행금지구역을 표시하는 API를 이용하여 드론비행금지구역을 나타내는 서비스를 구현한 결과를 보인다. GIS(Geographic Information System) 응용 프로그램인 QGIS에 WMS(Web Map Service)를 이용하여 오픈 API를 연동하였다. 항공정보도 API로부터 얻은 관제권 및 비행금지구역, 비행제한구역 레이어 등을 결합하여 드론 비행금지구역에 대한 데이터를 가진 새로운 레이어를 생성하였다.