• Korean Journal of Radiology
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• 제22권9호
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• pp.1481-1489
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• 2021

Objective: To construct a CT-based Fagotti scoring system by analyzing the correlations between laparoscopic findings and CT features in patients with advanced ovarian cancer. Materials and Methods: This retrospective cohort study included patients diagnosed with stage III/IV ovarian cancer who underwent diagnostic laparoscopy and debulking surgery between January 2010 and June 2018. Two radiologists independently reviewed preoperative CT scans and assessed ten CT features known as predictors of suboptimal cytoreduction. Correlation analysis between ten CT features and seven laparoscopic parameters based on the Fagotti scoring system was performed using Spearman's correlation. Variable selection and model construction were performed by logistic regression with the least absolute shrinkage and selection operator method using a predictive index value (PIV) ≥ 8 as an indicator of suboptimal cytoreduction. The final CT-based scoring system was internally validated using 5-fold cross-validation. Results: A total of 157 patients (median age, 56 years; range, 27-79 years) were evaluated. Among 120 (76.4%) patients with a PIV ≥ 8, 105 patients received neoadjuvant chemotherapy followed by interval debulking surgery, and the optimal cytoreduction rate was 90.5% (95 of 105). Among 37 (23.6%) patients with PIV < 8, 29 patients underwent primary debulking surgery, and the optimal cytoreduction rate was 93.1% (27 of 29). CT features showing significant correlations with PIV ≥ 8 were mesenteric involvement, gastro-transverse mesocolon-splenic space involvement, diaphragmatic involvement, and para-aortic lymphadenopathy. The area under the receiver operating curve of the final model for prediction of PIV ≥ 8 was 0.72 (95% confidence interval: 0.62-0.82). Conclusion: Central tumor burden and upper abdominal spread features on preoperative CT were identified as distinct predictive factors for high PIV on diagnostic laparoscopy. The CT-based PIV prediction model might be useful for patient stratification before cytoreduction surgery for advanced ovarian cancer.

• 방사선산업학회지
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• 제17권4호
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• pp.405-409
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• 2023

The magnetic resonance imaging method is a technology that can diagnose patients using local magnetic field through local magnetic field through local magnetic field through local magnetic field and STEAM method using local magnetic field Currently, many diseases can diagnose many diseases using self-resonance methods. The purpose of this study is to provide optimal information about using magnetic resonance imaging method according to patients.In many studies, self-resonance imaging showed that self-resonance methods can effectively inspect brain cancer and liver diseases. mong them, this study, brain tumor tests, cervical cancer tests based on literature, there were effective parts of these four diseases, but it was clearly found that they should not use in clinical trials, but it is clearly found to improve and improve and improve. Therefore, it is believed that it will be based on the future studies.

• 한국의학물리학회지:의학물리
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• 제19권4호
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• pp.298-304
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• 2008

본 연구에서는 다양한 관전압 사용에 따른 CR, DR 모의병변 흉부 영상을 이용하여 병변 검출 정도를 ROC 평가하였다. 모의 제작된 미세 폐 병변, 초기 침윤성 병변, 작은 혹 모양의 병변은 아크릴 판을 이용하여 인체형 흉부 팬텀과 포개놓고 영상을 획득하였으며 CR과 DR에서 각각 3개의 관전압(70 kV, 90 kV, 120 kV) 조건을 사용하였다. 총 18,000개의 관찰결과를 ROC평가 하였다. CR에서는 모든 병변에 대하여 70 kV로 획득한 영상이 높은 $A_z$값을 나타내었으나 DR에서는 두 개 병변에서만 70 kV로 획득한 영상이 높은 $A_z$값을 나타내었다. 본 연구내용을 바탕으로 검출기 종류와 관심 병변에 따른 최적의 관전압 조건을 사용하기 위하여 실제 환자에서의 임상 연구가 필요할 것으로 사료된다.

• 대한방사선기술학회지:방사선기술과학
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• 제47권3호
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• pp.197-203
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• 2024

During paranasal sinus X-ray examinations in children, the radiological technologist's thyroid shield is often not implemented to shorten the examination time. This study measured the radiation exposure before and after the implementation of thyroid shielding by analyzing the difference in radiation exposure, the radiological technologist's could receive depending on the actual thyroid shielding. In the left TLD, when thyroid shielding was not performed(N), the radiation exposure dose(mSv) was 2.869 for the depth dose[Hp(10)] and 2.886 for the surface dose[H(3)], and when thyroid shielding was performed(Y), the Hp(10) was 0.033 and the H(3) was 0.034. In the right TLD, when thyroid shielding was not performed(N), the radiation exposure dose was 3.149 for Hp(10) and 3.137 for H(3), and when thyroid shielding was performed, the Hp(10) of (Y) was 0.013 and the H(3) was 0.015. The differences in the overall exposure dose measurement values are all statistically significant (p<0.05). The difference in radiation dose between when thyroid shielding was not performed and when thyroid shielding was performed was more than 99.2% in both cases, indicating a high radiation shielding rate.

• 한국의학물리학회지:의학물리
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• 제18권3호
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• pp.144-148
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• 2007

최근 국내에서는 원거리에 있는 응급환자에 대한 원격의료서비스를 제공하기 위한 이동형 응급 의료 시스템에 대한 연구가 활발히 진행되고 있다. 본 연구의 목적은 응급구조 차에 탑재 할 수 있는 이동형 디지털 X선 촬영 장치를 구축하고 시스템으로부터 획득한 영상에 대하여 영상 성능평가의 주요인자인 MTF (modulation transfer function), NPS (noise power spectrum) 및 DQE (detective quantum efficiency)를 정량화함으로써 응급상황 시 임상적으로 효용성 있는 영상의 획득 가능성을 평가하는 것이었다. 이동형 X선 장치(Mobix-1000; LISTEM, Wonju, Korea)와 디지털 X선 detector 시스템 (Alpha-R4000; Teleoptic PRA, Kyiv, Ukraine)으로 구축된 영상시스템에 대하여 성능평가를 수행하였다. 측정결과로 10% MTF는 2.4 cycles/mm를 나타내었고, DQE (0)는 조건선량 0.19, 0.5 그리고 1.3 mR에 따라 각각 54%, 55%, 그리고 76%로 측정되었다. 본 연구에서 획득한 영상평가 결과는 연구 중인 이동형 디지털 X선 촬영 장치의 응급 원격 의료에의 사용가치를 확인 할 수 있는 기초자료로서 이용될 수 있을 것으로 판단된다.

• IEIE Transactions on Smart Processing and Computing
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• 제4권5호
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• pp.324-329
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• 2015

A decreased number of readout method is investigated to provide precise pixel information for small-animal positron emission tomography (PET). Small-animal PET consists of eight modules, and each module is composed of a $6{\times}6$ array of $2{\times}2{\times}20mm^3$ lutetium yttrium orthosilicate (LYSO) crystals optically coupled to a $4{\times}4$ array of $3{\times}3mm^2$ silicon photomultipliers (SiPMs). The number of readout channels is reduced by one-quarter that of the conventional method by applying a simplified row and column matrix algorithm. The performance of the PET system and detector module was evaluated with Geant4 Application for Emission Tomography (GATE) 6.1 and DETECT2000 simulations. In the results, all pixels of the $6{\times}6$ LYSO array were decoded well, and the spatial resolution and sensitivity, respectively, of the PET system were 1.75 mm and 4.6% (@ center of field of view, energy window: 350-650 keV).

• 한국환경성돌연변이발암원학회지
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• 제22권4호
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• pp.266-273
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• 2002

The dose dependence of the severity of radiation-induced thymic lymphoma in C57BL/6J mice was studied. Mice were exposed to fractionated irradiation at the total doses of 4.0, 6.0 and 8.0 Gy (four irradiations at 8-day intervals) starting from 33 days after birth. Pathological and histological changes of each mouse were observed after periodical sacrifice at day 75, 100, 125, 150, 175, 200, 250, 300 after the first irradiation. The severity of cancers were classified into 4 stages by clinical signs with respect to the enlargement of the thymus, spleen, liver, the progression of the cancer in the thymus, and the metastasis to the spleen, liver, lung and the lymphatic nodes. Among the 490 mice observed, 146 mice had thymic lymphoma. A clear dose-effect relationship was observed as well as the dose-response relationship. Also, periodical observation showed that thymic lymphoma was first induced in mice sacrificed at day 100 (130days old), and metastasize in the order of spleen, lung, liver and then the lymphatic nodes. The results suggest that radiation may be involved not only as a tumor initiator but also as a tumor promoter, and a tumor progression-enhancing agent.

• 대한방사선기술학회지:방사선기술과학
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• 제44권4호
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• pp.375-380
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• 2021

This study aim was quantitative assessment of MTFs of spectrum of the square wave chart images and Coltman chart images for 0°, 1.7°, 2.2°, 2.9°, 4.1° by using chart method. In general device was AccuRay-650 (DK Medical System, Korea) used, indirect flat panel detector(FPD) Aero (Konica, Japan) used and MATLAB R2019a (MathWorks, USA) used. The result of comparison for each angle of MTF the edge image was highest quantitatively value for MTF finding of showed the best value of 0.1 based on the frequency of 3.5 mm^-1, value of 0.1 based on the square wave was frequency of 3.0 mm^-1 and value of 0.1 based on the Coltman transform was frequency of 2.4 mm^-1. In this study it was significant that the methodology of the international Electro-technical Commission was applied mutandis by using the Fujita method within 2~3°.

• 대한방사선기술학회지:방사선기술과학
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• 제41권5호
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• pp.479-485
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• 2018

Radiologic technologists working at the second and third medical institutions are classified as radiation-related workers and radiation workers according to their working departments, and are subject to double regulation by the Ministry of Health and Welfare and the Nuclear Safety Commission. We will try to understand the system of dualization and to understand the investigation of recognition. The dualized system of radiation-related workers and radiation workers includes the difference in name and terminology, the effective dose limit, the maintenance education and training of radiologic technologists, the period of medical examination, the radiation zone, dose of the woman whose pregnancy is confirmed in radiologic technologists, the qualification criteria of the safety officer, and the period of the regular inspection of the radiological equipment. In the questionnaire survey on the dualization system, there were various items showing significant differences between the radiation-related workers and radiation workers Overall, the radiation workers were more aware of the radiation workers' education and related terms than the radiation-related workers.

• 대한방사선기술학회지:방사선기술과학
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• 제43권3호
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• pp.187-194
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• 2020

Bone mineral density is a examination to measure the amount of bone in patients with metabolic bone disease. It is a low dose, but may cause unnecessary exposure to the gonads and other organs located in the periphery when examining the lumbar and proximal femurs. Therefore, the purpose of this study was to evaluated the exposure dose for each organ exposed during the bone mineral density through simulation, and analyzed the applicability of the subject to radiation shielding devices using 3D printing materials. As a result, the highest dose was shown at 11.47 uSv in the breast during lumbar examination and 8.98 uSv in the testis during proximal femur examination. Also, the farther away from the examination site, the lower the effect of the scattering-ray. The shielding effect of using 3D printing shielding device showed high results in proportion to the effective atomic number and specific gravity of the printing material. Among the printing materials, ABS + W showed an effect of at least 78.72 to 96.3 9% compared to the existing lead material.