Earticle

본 연구의 목적은 급성기 허혈성 뇌졸중 환자의 뇌 관류 CT검사 시 피폭선량을 알아보고자 하였다. 특히, 방사선 감수성이 높은 장기들의 장기선량(Organ dose)을 팬텀과 유리선량계를 이용하여 실측해보고, 제조사가 제 시한 기존 프로토콜(고정시간기법)과 새로 제시한 융합 프로토콜(조영제 추적기법)을 적용하여 선량을 측정하여 보 고, 피폭선량 저감화 방안을 마련하고자 하였다. 분석결과 기존 프로토콜과 비교하여 새로 제시한 융합 프로토콜에 서 최고 39.8 %, 최저 5.8 % 장기선량이 감소하였고, 검사 피폭선량인 CDTIvol과 DLP 값은 각각 25 % 감소하였으 며, 권고 선량 이하로 측정되었다. 위의 분석결과를 바탕으로 기존에 제시된 프로토콜을 점검해보고, 새로 제시한 융합 프로토콜을 적용하여 피폭선량을 감소시켜 국민보건향상에 이바지 해야 할 것이며, 다른 검사에서도 최적의 프로토콜을 찾기 위한 연구가 계속되어져야 할 것으로 사료된다.

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 CDTIvol 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.

본 연구에서는 인터벤션 시술 시 사용하는 DSA에서 발생하는 높은 선량으로 시술자와 환자의 의료 피폭이 발생됨을 인지하고 3D printing DSA 팬텀을 이용하여 Cu filter와 post-processing algorithm의 적용을 통해 화질 저하를 개선한 저선량 프로토콜이 임상에 적용 가능한지를 알아봤다. 본원에서 3D Printing 기술을 이용하여 DSA 팬텀을 자체 제작하였으며, (1) 기존 프로토콜, (2) Cu filter 적용 프로토콜, (3) Cu filter 및 post-processing algorithm 적용 프로토콜로부터 획득한 영상의 선량, SNR&CNR, 정성적인 평가를 실시했다. Cu filter 0.3mm parameter 적용 전후로 61%의 선량 감소를 가져왔고, post-processing algorithm을 함께 적용했을 때 기존 Standard 프로토콜 대비 SNR은 93%, CNR은 98% 정량적인 수치를 나타냈다. 그리고 정성평가 결과에서는 93%의 인원이 임상에서 적합한 수준의 영상이라고 답변했다. Cu filter, post-processing algorithm을 통한 의료 피폭 선량 감소와 영상 화질 개선을 확인하고 기존 프로토콜을 대체할 저선량 프로토콜의 효용성을 입증했다

In this study, we recognized the high radiation dose during digital subtraction angiography (DSA) used in intervention procedures and used 3D-printed DSA phantom to determine whether low-dose protocol with post-processing algorithm is applicable to clinical procedures without deterioration of image quality. DSA Phantom was prepared by using 3D printing technology at the Asan medical center, and three imaging acquisition protocols were tested; (1) default protocol, (2) low-dose protocol with Cu filtration, (3) low-dose protocol with Cu filtration and post-processing algorithm according to radiation dose, SNR & CNR, and qualitative evaluation. It resulted in a 61% dose reduction before and after an adaption of 0.3mm Cu filtration, with 93% in SNR and 98% in CNR compared to the existing Standard protocol. In addition, 93% of the respondents said that the quality assessment was appropriate for clinical procedures. We identified that reduced radiation exposure dose and improved image quality through Cu filter, post-processing algorithm and demonstrated the utility of low-dose protocols could replace existing standard protocols.

Background: Whole-body counters are widely used to evaluate internal contamination of the internal presence of gamma-emitting radionuclides. In internal dosimetry, it is a basic requirement that quality control procedures be applied to verify the reliability of the measured results. The implementation of intercomparison programs plays an important role in quality control, and the accuracy of the calibration and the reliability of the results should be verified through intercomparison. In this study, we evaluated the reliability of 2 whole-body counting systems using 2 calibration methods. Materials and Methods: In this study, 2 whole-body counters were calibrated using a reference male bottle manikin absorption (BOMAB) phantom and a Radiation Management Corporation (RMC-II) phantom. The reliability of the whole-body counting systems was evaluated by performing an intercomparison with International Atomic Energy Agencyto assess counting efficiency according to the type of the phantom. Results and Discussion: In the analysis of counting efficiency using the BOMAB phantom, the performance criteria of the counters were satisfied. The relative bias of activity for all radionuclides was -0.16 to 0.01 in the Fastscan and -0.01 to 0.03 in the Accuscan. However, when counting efficiency was analyzed using the RMC- II phantom, the relative bias of 241Am activity was -0.49 in the Fastscan and 0.55 in the Accuscan, indicating that its performance criteria was not satisfactory. Conclusion: The intercomparison process demonstrated the reliability of whole-body counting systems calibrated with a BOMAB phantom. However, when the RMC-II phantom was used, the accuracy of measurements decreased for low-energy nuclides. Therefore, it appears that the RMC-II phantom should only be used for efficiency calibration for high-energy nuclides. Moreover, a novel phantom capable of matching the efficiency of the BOMAB phantom in low- energy nuclides should be developed.

We examined the accuracy and efficiency of phantom by applying the designed phantom in order to check daily quality assurance easily by objective criteria and to confirm daily quality assurance of linear accelerator, simulator, and CT-simulator. The results of 10 weeks of linear accelerator output dose using American Association of Physicists in Medicine(AAPM) daily quality assurance guide were measured within ±1% of error. Mechanical check of laser alignment, optical distance indicator(ODI), CT scanner laser and alignment of gantry lasers with the center of imaging plane were measured within ±1mm. Daily average working time for daily quality assurance of radiation therapy equipments was 38 minutes. The designed phantom was easy to install and daily quality assurance was possible with only one installation. The aspects reproducibility and efficiency as well as accuracy of quality assurance were excellent.

본 연구는 부산지역 의료기관과 대학에서 실습용으로 실제 사용 중인 초음파 영상진단장치의 성능을 평 가하기 위하여 고주파수 선형 탐촉자(Linear Probe)와 N-365 Multipurpose Phantom을 활용하였다. 8가지 평가 항목으로 구성하였으며 총 24대 장비 중 21대가 합격으로 평가되었다. 불합격으로 평가된 3대에서는 특히 측방향 분해능과 기능적 분해능의 1 [mm] 표적에서 p value 0.001 미만으로 나타나, 초음파장비 성능평가 합격 여부에 중요한 역할을 함을 확인하였다. 또한, 카이제곱 검정과 Mann-Whitney U 검정을 통해 기관별, 제조회사별, 장비 사용 연수에 따른 합격 여부의 차이를 분석한 결과, 기관과 제조회사별 합격 여부는 유의미한 차이가 없었으나 (p=0.489), 사용 연수에 따른 합격 여부는 유의미한 차이가 있었다(p=0.012). 이러한 결과는 초음파 영상진단장치 의 정확도와 신뢰성을 유지하기 위해서는 사용 연수에 따른 정기적인 성능평가와 품질 관리가 필수적이며 이는 초음파검사의 질을 향상시킬 수 있음을 보여준다.

This study evaluated the performance of ultrasound imaging system in use for training at medical institutions and universities in Busan, using high-frequency linear probes and the N-365 Multipurpose Phantom. The evaluation included eight criteria, and 21 out of 24 devices passed. The three that failed showed significant deficits in lateral resolution and functional resolution at the 1 [mm] target, with p values below 0.001, highlighting their importance in the performance assessments. Further analysis using Chi-square and Mann-Whitney U tests showed no significant differences in pass rates across institutions and manufacturers (p=0.489), but there were significant differences related to the years of use(p=0.012). These results emphasize the need for regular performance evaluations and quality control based on the age of the equipment, as proper management can enhance the quality of ultrasound examinations.

본 연구의 목적은 평면 모형의 가로, 세로 비율과 가상 cobb의 각도를 측정하는 등의 화상의 왜곡에 대한 비교 연구를 통해 3 spot DR 척추 전장 촬영 방법의 정확한 정보를 제공하는 것이다. 팬텀은 H(40cm) x V(116cm) x D(2.3cm) 크기로 납판이 삽입 된 격자형 아크릴로 만들었다. 제작 모형을 사용하여 각 장비에 각각 3회, OFD를 변경하여 총 9회 촬영하였고 납 격자의 가로, 세로 길이와 비율을 측정하였다. 또한 모형에서 임의의 지점을 지정하여 Cobb 각도를 측정하였다. 가로 세로 비율은 CR은 0.98~1.01, scan DR은 0.96~0.97, 3 spot DR은 0.99~1.01로 측정되었다. Cobb 각도는 각각 52.5~53.3o, 52.1~54.3o, 52.8~53.2o로 측정되었다. 실험 결과에 의해 평면 모형을 이용한 본 연구에서 척추 전장 촬영을 위한 3 spot DR 촬영 방식의 영상은 왜곡이 없는 정확한 방법이다.

The purpose of this study is to offer more accurate information in whole spine examination of 3 spot DR through the comparative study about image distortion as making the flat phantom and measuring horizontal, vertical ratio and cobb angle of the virtual. We produced H(40cm) x V(116cm) x D(2.3cm) flat acrylic phantom with lattice type of lead plate. We took projection respectively 3 times, total 9 times in each equipments using manufactured phantom as changing OFD to 6, 12, 18 cm. We measured a horizontal and vertical length of lead lattice and calculated the ratio. As appointing arbitrary points in the phantom and we measured cobb angle. The results of horizontal, vertical ratio measured CR type 0.98~1.01, scan DR type 0.96~0.97 and 3 spot DR 0.99~1.01. Cobb angle measured 52.5~53.3o, 52.1~54.3o and 52.8~53.2o. Finally we can say that 3 spot DR method is an accurate method without any distortion in whole spine radiography.

맥파는 심장에서 분출되는 혈액이 혈관을 지날 때 혈관벽을 따라 발생하는 압력파동으로 주로 동맥경화(arteriosclerosis) 등 혈관질환 진단 시 주요 지표로 활용된다. 맥파를 측정하는 가장 정확한 방법은 카테터를 이용해 혈관 내부의 압력변화를 직접 측정하는 방법이지만, 침습적 검사의 특성상 시술의 어려움, 감염위험 등의 단점이 존재한다. 이를 보완하기 위한 비침습적 방법으로 인체 외부에서 가압하여 혈관의 압력을 측정하는 토노메트리(tonometry) 방식과 빛을 이용하여 혈류량을 측정하는 광용적맥파(PPG, Photoplethysmography) 방식 등이 있다. 광용적맥파 측정 방식의 경우, 빛을 이용함에 따라 주변 환경 및 피측정자의 영향(호흡, 움직임 등)을 받기 쉬워 토노메트리 방식보다 정확한 측정이 쉽지 않다. 토노메트리식 맥파분석기의 경우 가압의 정도에 따른 맥파 신호의 변화를 통해 혈관의 경직도를 직접 측정할 수 있어 비교적으로 안정적인 맥파 측정이 가능하기 때문에 임상현장에서 주로 사용되고 있다. 2020년 초, 요골동맥에서 맥파를 측정하는 토노메트리식 맥파분석기의 성능평가 요구사항을 제시한 국제표준(ISO 18615)이 제정되면서 표준화·객관화된 맥파분석기 성능평가가 가능하게 되었다. 본 연구에서는 ISO 18615:2020에 따른 토노메트리식 맥파분석기의 성능평가에 적합한 평가도구로써 시뮬레이터(모의 맥파 생성기 및 압력 전달 매질)를 개발하고, 실제 상용 맥파분석기를 활용하여 해당 평가도구의 타당성을 검증하였다. 본 연구를 통해 개발된 평가도구 및 기술은 토노메트리식 맥파분석기의 일관된 품질관리에 활용됨으로써, 심혈관 건강 관리에 기여할 수 있을 것으로 예상된다.

Pulse waves are pressure waves that occur along the blood vessel walls when blood ejected from the heart passes through blood vessels, and are mainly used as a major indicator when diagnosing vascular diseases such as arteriosclerosis. The most accurate method of measuring pulse waves is to directly measure the pressure change inside a blood vessel using a catheter, but due to the nature of invasive tests, there are disadvantages such as difficulties in the procedure and risk of infection. Non-invasive methods to compensate for this include the tonometry method, which measures the pressure of blood vessels by applying pressure from outside the human body, and the photoplethysmography method, which measures blood flow using light. In the case of a photoplethysmography method, it is more susceptible to the influence of the surrounding environment and the subject (breathing, movement, etc.) as the light is used, making accurate measurement more difficult than the tonometric method. The tonometric pulse analyzer is mainly used in clinical settings because it is possible to directly measure the stiffness of blood vessels through changes in the pulse wave signal according to the degree of pressurization, enabling relatively stable pulse wave measurement. In early 2020, the international standard(ISO 18615), which specifies safety and performance requirements for tonometric pulse analyzer that measure pulse waves from the radial artery, was established, making standardized and objective pulse wave system performance evaluation became possible. In this study, we developed a simulator (simulated pulse wave generator and pressure transfer medium) as an evaluation tool suitable for performance evaluation of tonometric pulse analyzer according to ISO 18615:2020, and verified the validity of the evaluation tool by using an actual commercial pulse analyzer. The evaluation tools and technologies developed through this study are expected to contribute to cardiovascular health management by being used for consistent quality control of tonometric pulse analyzer.

Background: The reference dose coefficients (DCs) of the International Commission on Radiological Protection (ICRP) have been widely used to estimate organ doses of individuals for risk assessments. This approach has been well accepted because individual anatomy data are usually unavailable, although dosimetric uncertainty exists due to the anatomical difference between the reference phantoms and the individuals. We attempted to quantify the individual variation of organ doses for photon external exposures by calculating and comparing organ DCs for 30 individuals against the ICRP reference DCs. Materials and Methods: We acquired computed tomography images from 30 patients in which eight organs (brain, breasts, liver, lungs, skeleton, skin, stomach, and urinary bladder) were segmented using the ImageJ software to create voxel phantoms. The phantoms were implemented into the Monte Carlo N-Particle 6 (MCNP6) code and then irradiated by broad parallel photon beams (10 keV to 10 MeV) at four directions (antero-posterior, postero-anterior, left-lateral, right-lateral) to calculate organ DCs. Results and Discussion: There was significant variation in organ doses due to the difference in anatomy among the individuals, especially in the kilovoltage region (e.g. , <100 keV). For example, the red bone marrow doses at 0.01 MeV varied from 3 to 7 orders of the magnitude depending on the irradiation geometry. In contrast, in the megavoltage region (1–10 MeV), the individual variation of the organ doses was found to be negligibly small (differences <10%). It was also interesting to observe that the organ doses of the ICRP reference phantoms showed good agreement with the mean values of the organ doses among the patients in many cases. Conclusion: The results of this study would be informative to improve insights in individualspecific dosimetry. It should be extended to further studies in terms of many different aspects (e.g. , other particles such as neutrons, other exposures such as internal exposures, and a larger number of individuals/patients) in the future.

유방초음파는 타 의료영상과 비교하였을 때 매우 주관적이며 검사자의 숙련도 및 지식 정도에 따라 판독 결과가 달라질 수 있다는 문제점이 있다. 본 연구에서는 이를 보완하기 위한 방법으로 범용적으로 사용되고 있는 머신러닝 어플리케이션을 이용하여 유방초음파영상의 병변인식률을 살펴보고 이를 진단의 보조적인 방법으로 활용 할 수 있는 가능성을 고찰해 보고자 하였다. BreastFAN 유방초음파팬텀을 사용하여 정상과 양성·악성 종양조직 초음파영상 90개를 획득하여 관심영역을 설정한 후 Microsoft Lobe 프로그램을 이용하여 데이터를 학습시켜 머신 러닝모델을 구현하였다. 구현된 모델의 병변인식률 확인을 위해 유방초음파영상을 추출하여 인식률을 평가하였으 며 그 결과 평균 97.65%의 인식률을 나타냈다. 결론적으로 머신러닝 어플리케이션으로 구현된 모델은 유방초음파 병변분류에 있어서 보조진단시스템으로서 충분히 활용가능성이 있으며 경험이 부족한 검사자들에게 도움이 될 것 으로 판단된다.

Breast ultrasonography is very subjective compared to other medical images, and there is a problem that the reading result may vary depending on the level of skill and knowledge of the examiner. In this study, as a way to supplement this, we tried to examine the lesion recognition rate of breast ultrasound images using a machine learning application that is widely used and to consider the possibility of using it as an auxiliary method for diagnosis. Using the BreastFAN breast ultrasound phantom, 90 ultrasound images of normal, benign, and malignant tumor tissues were acquired, regions of interest were set, and a machine learning model was implemented by learning the data using the Microsoft lobe program. To confirm the lesion recognition rate of the implemented model, breast ultrasound images were extracted and the recognition rate was evaluated. As a result, the average recognition rate was 97.65%. In conclusion, it is judged that the model implemented as a machine learning application is sufficiently usable as an auxiliary diagnostic system in breast ultrasound lesion classification and will be helpful to examiners with sufficient experience.

본 연구에서는 X-ray장치(Drgem사 TS-CSP)와 foot phantom(SFT-1556)을 이용하여 발꿈치뼈 후전 축방향 촬영에서 X-ray 튜브의 각도를 30°, 35°, 40°, 45°, 50°로 변화를 주어 각 각도에 해당하는 영상을 흭득 한 뒤 정량적 평가와 정성적 평가로 나누어 영상을 평가하였다. 블라인드 테스트에서는 40°에서 4.34점으로 가장 높았으며 Image J 프로그램을 이용한 면적 계산에서는 각도가 50°에서 1750으로 가장 큰 값으로 나타났다. 또한 겹치는 부위를 제외한 면적 평가에서는 X-ray 튜브가 40°일 때 가장 큰 값을 보였다. 그러므로 발꿈치뼈를 관찰하기 위한 촬영법으로는 X-ray tube 각도가 40°일 때가 적합 하다는 결과를 얻었다.

In this study, using an X-ray device (Drgem TS-CSP) and foot phantom (SFT-1556), the angle of the X-ray tube was changed to 30°, 35°, 40°, 45°, and 50°, and the image was evaluated by quantitative and qualitative evaluation. In the blind test, it was the highest at 4.34 points at 40°, and in the part calculation using the Image J program, the angle was the largest at 1750 at 50°. In addition, in the area evaluation excluding overlapping areas, the X-ray tube showed the largest value at 40° Therefore, it was found that the X-ray tube angle was suitable when the X-ray tube angle was 40° as a projection method for observing the calcaneus.

환자맞춤형 의료기기는 의료영상을 이용하여 3차원 디지털 영상을 획득한 후 소재를 적층하여 제조한다. 모델 링 과정은 3D 프린팅 의료기기의 정확도에 영향을 미칠 수 있는 첫 번째 단계이므로 모델링 단계의 품질을 확보하 는 것이 중요하지만, 3D 모델링 소프트웨어로 설계된 제품이 적층제작한 제품과 일치하는지 평가할 표준화된 방법은 없는 상황이다. 국내·외 3D 프린팅 환자맞춤형 의료기기 정책과 국제규격, 가이드라인을 참고하면 제품과 3D 모델이 서로 일치하는지 확인하기 위해서는 제품 치수와 허용오차의 정확도 및 정밀도가 중요한 것으로 판단된다. 제품 해 상도를 최적화하여 형상을 정확하게 표현할 수 있는 것이 중요하며 STL(STereoLithography, STL) 파일의 오류가 발 생하지 않도록 기하학적 요구사항을 만족하여야 한다. 그리고 길이치수, 각도치수, 직진도, 평면도, 진원도, 원통도, 평 행도, 직각도, 위치도와 같은 치수공차와 기하공차는 3D 프린팅 모델링 소프트웨어를 평가하는 요소로 고려할 수 있 다. 본 연구를 통해 조사된 팬텀을 활용한 의료 3D 소프트웨어의 고려사항은 표준화된 의료 3D 모델링 소프트웨어 의 성능 평가 방법을 마련하는데 기여할 것으로 기대한다.

Patient-matched medical devices are manufactured by stacking materials after obtaining 3D digital images using medical images. As the modeling process is the first step that can affect a 3D printed medical device's accuracy, it is crucial to ensure the quality of the modeling step. Still, there is no standardized way to evaluate whether a product designed with 3D modeling software matches a custom-made product. Based on the domestic and overseas 3D printing patient customized medical device policies, international standards, and guidelines, it is considered that the accuracy and precision of product dimensions and tolerance errors are important to check whether the product and 3D models match each other. It is crucial to accurately express the shape by optimizing the product resolution, and geometric requirements must be satisfied to prevent errors in the STL file. Dimensional and geometrical tolerances by geometric methods such as length dimension, angular dimension, straightness, flatness, roundness, cylindricity, parallelism, perpendicularity, and position can be considered factors for evaluating 3D printing modeling software. This study's consideration of medical 3D software using phantom investigated is expected to contribute to preparing a standardized medical 3D modeling software performance evaluation method.

Background: In recent events of the coronavirus disease 2019 (COVID-19) pandemic, computed tomography (CT) scans are being globally used as a complement to the reverse-transcription polymerase chain reaction (RT-PCR) tests. It will be important to be aware of major organ dose levels, which are more relevant quantity to derive potential long-term adverse effect, for Korean pediatric and adult patients undergoing CT for COVID-19. Materials and Methods: We calculated organ dose conversion coefficients for Korean pediatric and adult CT patients directly from Korean pediatric and adult computational phantoms combined with Monte Carlo radiation transport techniques. We then estimated major organ doses delivered to the Korean child and adult patients undergoing CT for COVID-19 combining the dose conversion coefficients and the international survey data. We also compared our Korean dose conversion coefficients with those from Caucasian reference pediatric and adult phantoms. Results and Discussion: Based on the dose conversion coefficients we established in this study and the international survey data of COVID-19-related CT scans, we found that Korean 7-yearold child and adult males may receive about 4–32 mGy and 3–21 mGy of lung dose, respectively. We learned that the lung dose conversion coefficient for the Korean child phantom was up to 1.5-fold greater than that for the Korean adult phantom. We also found no substantial difference in dose conversion coefficients between Korean and Caucasian phantoms. Conclusion: We estimated radiation dose delivered to the Korean child and adult phantoms undergoing COVID-19-related CT examinations. The dose conversion coefficients derived for different CT scan types can be also used universally for other dosimetry studies concerning Korean CT scans. We also confirmed that the Caucasian-based CT organ dose calculation tools may be used for the Korean population with reasonable accuracy.

학교에서 의료용 초음파 실습 시 초음파 장치의 Freeze 및 Print Button, 프로브의 Lens, 손잡이, Line 부분 그리고 복부 Phantom에서 가장 접촉이 많은 부위를 임의로 선정하여 프로브에 상제하고 있는 세균을 검출하여 병원균 의 수를 알아보고자 한다. 실험 방법으로는 실험 대상 위치에 균채집용 멸균된 면봉으로 검사 대상 부위를 20번 문지른 후 Lysogeny broth(LB) agar에 도말을 실시한 후 배양기에 넣어 48시간 동안 배양하고 colony forming unit (CFU) 수를 평가하여 프로브 손잡이, 복부 Phantom의 세균 분포정도를 알아보았다. 그 결과 CFU 값은 Lens는 3.0±0.87, Print button는 5.5±1.06, Freeze button은 8.0±4.95, Phantom은 20.0±2.78, Line은 23.5±2.50, 그리고 Probe handle의 값은 35.3±10.75로 측정되었다. 본 연구에서는 의료용 초음파 실습 시 실습 시 장비의 감염관리에 대한 주의를 부각시키고, 나아가서 초음파 장치의 세균 감염률 감소에 확실하게 기여 할 수 있을 것으로 기대된다.

During the medical ultrasound exercise at school, we randomly select parts of the ultrasound device and areas with the most contact in the abdominal phantom to detect bacteria that are above the probe and determine the number of pathogens. I want to find out. The experimental method was rubbed 20 times with the sterilized cotton swab for sterilization and then smeared on Lysogeny broth (LB) agar, put into the incubator and incubated for 48 hours, and the colony forming unit (CFU) count was measured. The bacterial distribution of probe handle and abdominal phantom was evaluated by evaluation .As a result, the CFU value is the lens was 3.0 ± 0.87, print button was 5.5 ± 1.06, freeze button was 8.0 ± 4.95, phantom was 20.0 ± 2.78, line was 23.5 ± 2.50, and probe handle was measured as 35.3 ± 10.75. In this study, it is expected that attention to infection control of equipment during practice during medical ultrasound practice can be highlighted and further contributed to the reduction of bacterial infection rate of ultrasound devices.

본 연구는 복부 전산화단층촬영 검사에서 X-축 방향의 회전에 따른 선량, 영상의 화질을 평가하여 피폭선량의 감소 방안을 평가 하였다. 인체 모형 팬텀을 이용해 0도, 5도, 10도, 15도로 5도씩 X-축 방향으로 회전하여 scan을 하였다. 각각의 회전에서 CTDIvol 값, HU, 노이즈, 그리고 신호대잡음비를 측정하였다. SPSSWIN(ver 19.0) 프로그램을 사용하여 ANOVA 분석을 하였다. 회전에 따른 선량은 0도, 5도, 10도, 15도 회전에서 각각 5.44mGy, 5.70mGy, 5.98mGy, 6.38mGy 측정되었다. 회전에 따른 HU, 노이즈, 그리고 신호대잡음비는 통계적으로 유의한 차이가 없었다. 전산화단층촬영 검사에서 환자가 gantry aperture의 isocenter에 위치함과 동시에 X-축 방향으로 회전이 없다면 피폭 선량이 감소되어진다.

The purpose of this study was to evaluate the dose and image quality according to the rotation of the X-axis direction in the abdominal CT scan, and to find ways to reduce the exposure dose. The phantom was scanned by rotating in the X-axis direction at 0, 5, 10, and 15 degrees, respectively. The CTDIvol value, HU, noise, and signal-to-noise ratio were measured at each rotation. ANOVA analysis was performed using the SPSSWIN (ver 19.0) program. The radiation exposure dose was 5.44mGy, 5.70mGy, 5.98mGy and 6.38mGy at 0, 5, 10 and 15 degrees, respectively. HU, noise, and signal-to-noise ratio were not statistically significant. In the CT scan, if the patient is located in the isocenter of the gantry aperture and there is no rotation in the X-axis direction, the exposure dose is reduced.

중증외상 환자 CT(Computed Tomography)검사 시 검사 보조자의 방사선 피폭경감을 위하여 새로운 융합적 모델의 망토 차폐체를 제작하여 그 유용성을 평가하고자 한다. 실험 방법으로 뇌혈관 CT 검사와 동일한 조건에서 두부 팬텀과 인체 팬텀을 이용하여 기존 차폐체와 새롭게 개발된 망토 차폐체를 이용하여 심장, 양쪽 액와부 그리고 갑상샘 부위를 유리선량계로 피폭선량을 측정하였다. 새롭게 개발된 차폐체가 기존의 차폐체 보다 방사선 차폐율이 심장 61.9 %, 좌측액와부 46.2 %, 우측액와부 69.8 %, 그리고 갑상샘 71.1 % 로 각각 높게 측정되었다. 새롭게 개발된 망토 차폐체가 방사선 피폭을 감소시키는데 매우 유용하며 향후 새롭게 개발된 융합적 모델의 망토 차폐차가 방사선 피폭을 감소시키는데 있어 큰 기여를 할 것으로 판단된다.

The purpose of this study is to evaluate the usefulness of a newly fusion model designed cloak shield to reduce the radiation exposure of the assistant during CT(computed tomography) of severely injured patient. Radiation dose was measured in the heart, both axillary and thyroid areas using newly designed cloak shield and existing shield with head phantom and human phantom under the same conditions as brain vascular CT scan. The newly designed cloak shield was measured higher for radiation shielding rate than the existing shields, 61.9 % for heart, 46.2 % for left axillary, 69.8 % for right axillary and 71.1 % for thyroid gland, respectively. a newly developed fusion model of cloak shields are useful for reducing radiation exposure. It is expected to make a significant contribution to reduction of radiation exposure.