• Safety and Health at Work
• /
• 제12권4호
• /
• pp.445-451
• /
• 2021

Background: This study aimed to evaluate the reliability and validity of the self-administered questionnaire for Korean radiation workers. Methods: From May 24, 2016, to June 30, 2017, 20,608 participants completed the questionnaire, providing information on sociodemographics, lifestyle, work history and practices, medical radiation exposure, and medical history, which was linked to the National Dose Registry and the National Cancer Registry. The validity of the questionnaire was evaluated using the responses of 20,608 workers, and reliability was evaluated using the responses of 3043 workers who responded to the survey twice. Results: Responses concerning demographic characteristics and lifestyle showed reliability with a moderate-to-high agreement (kappa: 0.43-0.99), whereas responses concerning occupation and medical radiation exposure had a wide range of agreement (kappa: 0.05-0.95), possibly owing to temporal variability during employment. Regarding validity, responses to the question about the first year of employment had an excellent agreement with the national registry (intraclass correlation coefficient = 0.9); however, responses on cancer history had a wide range of agreement (kappa: 0.22-0.85). Conclusion: Although the reliability and validity of the questionnaire were not distinguished by demographic characteristics, they tended to be low among participants whose occupational radiation exposure was minimal. Overall, the information collected can be reliable for epidemiological studies; however, caution must be exercised when using information such as medical exposure and work practices, which are prone to temporal variability.

• 대한방사선기술학회지:방사선기술과학
• /
• 제46권4호
• /
• pp.325-336
• /
• 2023

The purpose of this study was to analyze the structural relationship between job satisfaction levels felt during ultrasound examination of radiological technologists (RTs) using a structural equation model. The subjects were a total of 203 RTs currently working in medical institutions. The method was conducted as a survey study using a questionnaire consisting of a total of 29 questions consisting of demographic characteristics and job satisfaction levels that were self-efficacy, job competency, extrinsic compensation, and job satisfaction. The reliability was secured with the Cronbach's alpha coefficient of 0.6 or higher. For statistical analysis, a significant difference between the frequency analysis of demographic characteristics and the mean of the job satisfaction levels were performed by independent sample T-test and one-way analysis of variance (ANOVA) followed by Scheffe's post hoc test. The correlation analysis between variables was tested with Spearman's and Pearson's correlation coefficient. We analyzed the structural relationships between variables by structural equations. As a result, first, job competency and extrinsic compensation had a positive effect on job satisfaction on ultrasound examination of RTs. Second, the self-efficacy of ultrasound examination RTs showed a high correlation with job competency. Third, the job satisfaction levels showed in the order of job competency, job satisfaction, self-efficacy, and extrinsic compensation. In conclusion, this study are expected to be provided as data to identify factors that could improve job satisfaction during ultrasound examination of RTs by empirically analyzing the structural relationship of self-efficacy, job competency, and external compensation.

• 방사성폐기물학회지
• /
• 제18권2호
• /
• pp.195-206
• /
• 2020

국내 방사능재난대응체계는 일본 후쿠시마 원전 사고와 최근의 국내 대형 재난 교훈 등을 바탕으로 개선돼 오고 있지만, 아직 방사능재난 특성과 후쿠시마 원전 사고 교훈을 완전히 반영하고 있지 못하다. 하나의 방사능재난대응체계에 복수의 국내법이 적용되면서, 실제 상황 시, 대응체계의 실효성을 훼손할 가능성이 있는 법 조항 간 불일치 사항이 존재하기도 한다. 이에 본 논문에서는 방사능재난대응 속성을 분석하고, 방사능재난대응체계 적절성 측면에서 「재난 및 안전관리 기본법」과 「원자력시설 등의 방호 및 방사능 방재 대책법」에서 규정한 방사능재난대응체계, 후쿠시마 원전 사고 시 일본측의 방사능 재난 대응 활동을 분석하고, 이 분석결과를 토대로, 대응체계와 조직 측면에서 국내 방사능재난대응체계 실효성을 제고하기 위해 필요한 개선사항을 도출하여 제시하였다.

• 대한방사선기술학회지:방사선기술과학
• /
• 제45권1호
• /
• pp.11-17
• /
• 2022

This study was purpose to quantitative assessment of the resolution characteristics by using American college of radiology(ACR) phantom for magnetic resonance imaging (MRI). The MRI equipment was used (Achiva 3.0T MRI, Philips system, Netherlands) and the head/neck matrix shim SENSE head coil were 32 channels(elements) receive MR coil. And the MRI equipment was used (Discovery MR 750, 3.0T MRI, GE medical system, America) and the head/neck matrix shim MC 3003G-32R 32-CH head coil were receive MR coil. As for the modulation transfer function(MTF) comparison result by using ACR magnetic resonance imaging phantom, the MTF value of the ACR standard T2 image in GE equipment is 0.199 when the frequency is 1.0 mm^-1 and the MTF value of the hospital T2 image in Philips equipment is 0.528. It was used efficiently by using a general sequence more than the standard sequence method using the ACR phantom. In addition it is significant that the quantitative quality assurance evaluation method for resolution characteristics was applied mutatis mutandis, and the result values of the physical image characteristics of the 3.0T MRI device were presented.

• 대한방사선기술학회지:방사선기술과학
• /
• 제28권1호
• /
• pp.55-65
• /
• 2005

서울, 경기 지역의 중소 병 의원 회원들의 근무환경 실태를 파악하여, 국민보건증진과 무면허자의 방사선 검사업무 금지, 사기진작과 불만족해소, 직무만족도를 높여 복지와 권익을 향상, 정책 참여를 유도, 근무환경 개선에 목적이 있다. 2003년 7월부터 8월까지 271명을 대상으로 일반적 기본사항, 병실 수, 고용실태, 고용 및 업무범위, 이직빈도, 고용계약서 작성여부, 임금실태, 근무환경, 방사선사 호칭, 방사선안전관리, 품질관리, 방사선 차폐시설, 영상획득시스템, 필름시스템 종류, 장비보유현황, 방사선 피폭 방어기구, 협회와 관련된 항목을 설문 조사하였다. 근무환경, 불만족 문제점을 파악하여, 합리적이고 나은 근무환경을 제공하는 기초 자료로 활용하는데 이용하고, 근무환경 및 근무제도, 직제의 개선을 가져올 수 있도록 협회와 회원은 노력하여야한다. 주기적으로 설문조사를 실시하고 불만족을 해소하는 정책을 추진하도록 한다.

• 대한방사선기술학회지:방사선기술과학
• /
• 제1권1호
• /
• pp.55-59
• /
• 1978

The photographic characteristics have been studied in relation with various molecular weights of Polyvinylpyrrolidone(PVP). The shape of silver halogen crystals by physical ripening of mixture of photographic gelatine and various molecular weights of PVP were observed. Then, the photographic characteristics have been studied by chemical ripening. Results were concluded as follows: 1. All of the crystals have formed in the shape of (100) or (111). 2. Photographic characteristics were inferior by using PVP of higher molecular weight. 3. Photographic characteristics were superior by using PVP of lower molecular weight. 4. Photographic characteristic were compared with various Emulsion thickness and Tested Resolving power.

• 한국방사선학회논문지
• /
• 제15권1호
• /
• pp.9-14
• /
• 2021

방사선에 의한 피폭 없이 대조도가 우수한 영상의 획득이 가능한 자기공명영상은 진단에 필수적이지만 영상에서의 노이즈 발생은 불가피한 요소이기 때문에 이를 보완하기 위해 자기공명영상장치의 변수들을 조절하여 우수한 특성을 가진 영상을 획득할 수 있다. 이 중, 여기횟수 (NEX; number of excitation)는 추가적인 영상 특성의 저하 없이 우수한 특성의 영상을 획득할 수 있지만 scan time이 증가하여 motion artifact를 발생시킬 수 있고, scan time의 증가에 비례하여 영상의 특성이 향상되지 않기 때문에 적절한 NEX의 설정이 필요하다. 따라서, 본 연구에서는 MRiLab simulation program을 통해 자기공명영상의 모든 변수들을 고정시킨 후, NEX만을 조절하여 획득한 뇌 T2 강조 영상의 정량적 평가를 통해 NEX 변화에 따른 영상 특성의 경향성을 평가하고자 하였다. 획득한 영상의 노이즈 레벨 및 유사도 평가를 하기 위해 신호 대 잡음비 (SNR; signal to noise ratio), 대조도 대 잡음비 (CNR; contrast to noise ratio), 평균 제곱근 오차 (RMSE; root mean square error) 그리고 최대 신호 대 잡음비 (PSNR; peak signal to noise ratio)를 계산하였다. 결과적으로, 노이즈 레벨 및 유사도 평가 인자 모두 NEX가 증가함에 따라 개선된 값을 보였으나, 점차 증가폭이 감소함을 보였다. 따라서, 과도하게 큰 NEX는 장시간의 scan에 따른 motion artifact를 발생시켜 영상 특성을 저하시킬 수 있으므로, 적절한 NEX의 설정이 중요함을 확인하였다.

• 대한방사선기술학회지:방사선기술과학
• /
• 제39권2호
• /
• pp.157-161
• /
• 2016

본 연구에서는 자체 제작한 3종의 초음파 TM 팬텀의 음향학적 특성 및 온도 민감도를 측정하였으며, 초음파 영상학적 특성을 관찰, 평가하였다. TM 팬텀은 폴리우레탄을 주재료로 국제전기표준회의(International Electronical Committee, IEC) 기준안에 따라 제작하였으며 외부 온도 변화 따른 초음파 영상학적 특성은 $22^{\circ}C$ 이하에서 온도감소에 따라 휘도 및 영상투과심도가 비례하여 감소하는 것이 확인되었다. 본 연구를 통하여 산란재 특성이 상이한 TM 팬텀을 제작하는 기초자료를 제공하였으며, TM 팬텀의 사용 온도는 $22^{\circ}C$ 이상에서 사용하는 것이 적합한 것으로 판단되었다.

• Tuberculosis and Respiratory Diseases
• /
• 제84권3호
• /
• pp.209-216
• /
• 2021

Background: Endobronchial lung cancer (EBLC) and bronchial anthracofibrosis (BAF) share similar symptoms and radiological findings. The aim of this study was to describe clinical and radiological differences between BAF and EBLC, both of which were confirmed by bronchoscopy. Methods: This was a retrospective study of patients with BAF or EBLC from 2008 to 2014. Data were derived from a bronchoscopy registry made since January 1, 2008. Clinical and radiological characteristics of both diseases were analyzed. Results: Among 3,214 patients who underwent bronchoscopy, 167 and 117 patients were enrolled in BAF and EBLC groups, respectively. BAF occurred more predominantly in older non-smoking female patients with a higher chance of tuberculosis (38.3%) than EBLC (6.0%). Cough, sputum, and dyspnea were common symptoms reported for both groups. Bronchoscopic findings revealed that BAF lesions were more common in multiple lobar bronchi (85.0%) or bilateral bronchi (73.7%). Radiologic findings revealed that bronchial stenosis was the most commonly found lesion in both groups (49.1% and 78.6%, respectively). Rates of peribronchial calcification and bronchial wall thickening were higher in the BAF group. The number of patients with lymph node calcification was also higher in the BAF group. Conclusion: Results of this study demonstrated characteristics of clinical and radiologic findings of BAF and EBLC. Increasing the awareness of both diseases may help clinicians differentiate these two diseases from each other, thus avoiding unnecessary invasive diagnostic procedures.

• Nuclear Engineering and Technology
• /
• 제53권12호
• /
• pp.4122-4129
• /
• 2021

The counting efficiencies obtained using anthropomorphic physical phantoms are generally used in whole-body counting measurements to determine the level of internal contamination in the body. Geometrical discrepancies between phantoms and measured individuals affect the counting efficiency, and thus, considering individual physical characteristics is crucial to improve the accuracy of activity estimates. In the present study, the counting efficiencies of whole-body counting measurements were calculated considering individual physical characteristics by employing Monte Carlo simulation for calibration. The NaI(Tl)-based stand-up and HPGe-based bed type commercial whole-body counters were used for calculating the counting efficiencies. The counting efficiencies were obtained from 19 computational phantoms representing various shapes and sizes of the measured individuals. The discrepancies in the counting efficiencies obtained using the computational and physical phantoms range from 2% to 33%, and the results indicate that the counting efficiency depends on the size of the measured individual. Taking into account the body size, the equations for estimating the counting efficiencies were derived from the relationship between the counting efficiencies and the body-build index of the subject. These equations can aid in minimizing the size dependency of the counting efficiency and provide more accurate measurements of internal contamination in whole-body counting measurements.