• 대한방사선기술학회지:방사선기술과학
• /
• 제43권5호
• /
• pp.323-329
• /
• 2020

The purpose of this study is to investigate the effect of radiation shielding on the thyroid organ dose and image quality during Chest PA examination using automatic exposure control system. This study was conducted in the patient posture and examination conditions such as Chest PA using human model phantom. An experiment without shielding was set as a control group (non) and the cases of using paper coated with a contrast agent (contrast) and bismuth (bismuth) were used as experimental groups. Compared to non-shielded(non), the dose at bismuth increased about 7% in C(cervical vertebrae)5 and C6 and 14% in C7 and contrast showed dose increases of about 17 to 19% in C5 and C6 and about 21% in C7. As a result of the image quality comparison, when measured in the center of the cervical vertebrae, both SNR and CNR in bismuth increased about 40% higher than non, and contrast showed about 8 to 9% improvement. Compared with soft tissues of the cervix, bismuth reduced SNR by about 15% and CNR by about 13%, in contrast, SNR decreased by 11%, and CNR decreased by about 10%. In the Chest PA using AEC, the method of using the shield in front of the collimator has the advantage to observe the anatomical structure of the neck area well compared to the method using the lead. However, the dose at the neck can be increased by 7-21% depending on shielding materials.

• Journal of Trauma and Injury
• /
• 제22권1호
• /
• pp.24-28
• /
• 2009

Purpose: This was conducted to assess the need for conventional radiographs of the thoracolumbar spine for routine screening of trauma patients who revealed no spinal trauma on chest and abdominal computed tomography (CT). Methods: We performed a retrospective review of the medical records of trauma patients who underwent conventional radiographs of the thoracolumbar spine following a chest and abdominal CT that revealed no spinal trauma. Results: Two hundred seventy-five trauma patients underwent conventional radiographs of the thoracolumbar spine following a chest and abdominal CT that revealed no spinal trauma. In 274 of the cases, the thoracolumbar spine series was also negative. Conclusion: CT of the chest and abdomen is an adequate evaluation of the thoracolumbar spine in trauma patients who require routine thoracolumbar spine screening, making subsequent conventional radiographs of the thoracolumbar spine unnecessary.

• 대한방사선기술학회지:방사선기술과학
• /
• 제30권4호
• /
• pp.335-341
• /
• 2007

Simple chest radiography에서 정상인의 가로막(diaphragm)에 대한 계측치는 다음과 같다. 1. 전체 대상자에 대한 흉곽(internal diameter of thorax: ID)의 평균은 293.3 mm이었으며, 최소 221.0 mm, 최대 335.3 mm이었다. 2. 가로막의 높이는 오른 가로막이 높은 경우가 81.4%, 오른 가로막과 왼 가로막이 동일한 경우가 16.2%, 왼 가로막이 높은 경우가 2.4% 순으로 나타났다. 3. 오른 가로막이 높은 경우 오른 가로막의 평균 높이는 15.2 mm이었으며, 가장 낮은 경우는 2.0 mm, 가장 높은 경우는 41.7 mm이었다. 4. 왼 가로막이 높은 경우 왼 가로막의 평균 높이는 11.5 mm이었으며, 가장 낮은 경우는 4.7 mm, 가장 높은 경우는 30.4 mm이었다. 5. 가로막의 만곡도에서 오른 가로막의 평균 만곡은 22.9 mm이었고, 가장 작은 경우는 10.4 mm, 가장 큰 경우는 37.3 mm이었다. 6. 왼 가로막의 평균 만곡은 22.4 mm이었고, 가장 작은 경우는 11.3 mm, 가장 큰 경우는 42.2 mm이었다. 7. ID와 오른 가로막과 왼 가로막 만곡에 대한 관계에서 ID는 오른 가로막 만곡(r= .427, p<.001)과 왼 가로막 만곡(r= .425, p<.001)에서 모두 통계적으로 유의미한 정적 상관관계를 보였다. 8. 오른 가로막 만곡과 왼 가로막 만곡의 관계는(r= .403, p<.001) 통계적으로 유의미한 정적 상관관계를 보였다.

• 한국방사선학회논문지
• /
• 제15권1호
• /
• pp.55-61
• /
• 2021

방사선 촬영실은 감염원을 지닌 환자와 간접적인 접촉이 빈번하게 일어나 2차 감염에 노출될 위험성이 높다. 따라서 본 연구는 흉부 X선 촬영을 대상으로 방사선사와 환자가 빈번하게 접촉하는 부위를 4급 암모늄세정제 중 하나인 에니오설프(ANIOS, ANIOSURF Premium NPC)를 이용하여 소독 전, 후의 미생물을 채z취한 후 비교하였다. 2020년 9월 1일부터 9월 7일까지 대구광역시 P병원을 대상으로 X-ray tube handle, Chin rsgion, Chest region, Palm region을 수송배지(TransystemTM, Copan Diagnostics Inc., Murrieta, CA, USA) 내의 멸균면봉을 사용하여 10×10㎠ 크기로 채취한 후 비색법을 통해 소독 전, 후 동정결과를 획득하였다. 그 결과 X-ray tube handle의 경우 Proteus mirabilis, Staphylococcus epidermidis, Bacillus spp., Candida spp이 검출되었고, Chin region의 경우 Proteus mirabilis, Enterococcu faecium, Pseudomonas aeruginosa, NTM이 검출되었고, Chest region의 경우 Proteus mirabilis, Enterococcu faecium, Pseudomonas aeruginosa이 검출되었고, Palm region의 경우 NTM, Candida spp.이 검출되었으며 공통적으로 103 CFU(Colony Forming Unit) 이상이 측정되었다. 소독 후 Chest region, Palm region에서는 미생물이 검출되지 않았고 X-ray tube handle에서만 Bacillus spp.이 검출되었으며 102 CFU 이상이 측정되었다. 소독 전 검출된 미생물은 대부분 기회감염균의 일종으로 소독 후 이러한 미생물의 수가 줄어들거나 제거되는 것을 통해 에니오설프(0.25%)는 에탄올(ethanol, 70~90%)와 이소프로필 알코올(Isopropyl alcohol, 70~90%)과 비교하였을 때 우수한 경제성과 유사한 소독효율을 보였다. 하지만 소독 후 Bacillus spp.가 검출됨에 따라 아포균에 대한 심화된 연구가 필요하다고 생각된다. 본 연구는 방사선 검사실 내 감염관리의 중요성을 재고하였으며 병원 내 2차 감염을 예방하기 위한 유용한 기초자료로 사용될 것으로 사료된다.

• 대한방사선기술학회지:방사선기술과학
• /
• 제26권4호
• /
• pp.11-19
• /
• 2003

수도권에 소재하는 의료기관 44개 곳에서 시행하는 흉부X선 간접촬영에서 사용한 간접촬영 필름의 크기에 따라 촬영조건, 화상의 물리적 평가 및 시각적 평가, 조사선량 등을 조사한 결과 아직도 대부분 저관전압 촬영을 하고 있어 적절한 촬영조건 개선이 필요하며, 화상평가 비교에서 물리적 평가에서는 비슷한 결과를 보였으나 시각적 평가에서는 100mm 필름을 사용한 경우가 70mm 필름을 사용한 경우보다 대체적으로 우수한 것으로 나타났고, 흉부표면에 조사되는 선량은 70mm 필름을 사용한 경우가 100mm 필름을 사용한 경우보다 3배 이상의 피폭이 더 되고 있어 환자의 피폭선량 경감과 화질개선에 있어서 필름 선택의 중요성을 재삼 인식시켜 주었다.

• Tuberculosis and Respiratory Diseases
• /
• 제86권3호
• /
• pp.226-233
• /
• 2023

Background: Inactive or old, healed tuberculosis (TB) on chest radiograph (CR) is often found in high TB incidence countries, and to avoid unnecessary evaluation and medication, differentiation from active TB is important. This study develops a deep learning (DL) model to estimate activity in a single chest radiographic analysis. Methods: A total of 3,824 active TB CRs from 511 individuals and 2,277 inactive TB CRs from 558 individuals were retrospectively collected. A pretrained convolutional neural network was fine-tuned to classify active and inactive TB. The model was pretrained with 8,964 pneumonia and 8,525 normal cases from the National Institute of Health (NIH) dataset. During the pretraining phase, the DL model learns the following tasks: pneumonia vs. normal, pneumonia vs. active TB, and active TB vs. normal. The performance of the DL model was validated using three external datasets. Receiver operating characteristic analyses were performed to evaluate the diagnostic performance to determine active TB by DL model and radiologists. Sensitivities and specificities for determining active TB were evaluated for both the DL model and radiologists. Results: The performance of the DL model showed area under the curve (AUC) values of 0.980 in internal validation, and 0.815 and 0.887 in external validation. The AUC values for the DL model, thoracic radiologist, and general radiologist, evaluated using one of the external validation datasets, were 0.815, 0.871, and 0.811, respectively. Conclusion: This DL-based algorithm showed potential as an effective diagnostic tool to identify TB activity, and could be useful for the follow-up of patients with inactive TB in high TB burden countries.

• Korean Journal of Radiology
• /
• 제21권11호
• /
• pp.1265-1272
• /
• 2020

Objective: We investigated the prevalence of pneumonia in novel coronavirus disease 2019 (COVID-19) patients using chest radiographs to identify the characteristics of those with initially negative chest radiographs, who were positive for pneumonia on follow-up. Materials and Methods: Retrospective cohort data of 236 COVID-19 patients were reviewed. Chest radiography was performed on admission, with serial radiographs obtained until discharge. The 'positive conversion group' was defined as patients whose initial chest radiographs were negative but were positive for pneumonia during follow-up. Patients with initially positive chest radiographs were defined as the 'initial pneumonia group.' Patients with negative initial and follow-up chest radiographs were defined as the 'non-pneumonia group.' Clinical and laboratory findings were compared between groups, and predictors of positive conversion were investigated. Results: Among 236 patients, 108 (45.8%) were in the non-pneumonia group, 69 (29.2%) were in the initial pneumonia group, and 59 (25%) were in the positive conversion group. The patients in the 'initial pneumonia group' and 'positive conversion group' were older, had higher C-reactive protein (CRP) and lactate dehydrogenase levels, and lower absolute lymphocyte counts than those in the 'non-pneumonia group' (all p < 0.001). Among patients with negative initial chest radiographs, age ≥ 45 years (odds ratio [OR]: 3.93, 95% confidence interval [CI]: 1.76-8.75, p = 0.001), absolute lymphocyte count < 1500 cells/μL (OR: 2.25, 95% CI: 1.03-4.89, p = 0.041), and CRP > 0.5 mg/dL (OR: 3.91, 95% CI: 1.54-9.91, p = 0.004) were independent predictors for future development of pneumonia. Conclusion: More than a half of COVID-19 patients initially had normal chest radiographs; however, elderly patients (≥ 45 years of age) with abnormal laboratory findings (elevated CRP and low absolute lymphocyte counts) developed pneumonia on follow-up radiographs.

• 대한방사선기술학회지:방사선기술과학
• /
• 제42권6호
• /
• pp.477-482
• /
• 2019

Recently, due to the increased use of medical radiation, the radiation exposure of radiation workers should be considered as well as medical exposure of patients. And it is recommended to close the door during radiography. however, In this study, when the door was inevitably opened for radiography, the proposed method was to install the shield as a method of reducing the exposure dose. And its efficiency was analyzed. In simple chest radiography, the measurement point was changed according to the measurement location. Dose rate were measured 10 times for each condition using a dosimeter. And the average value was derived. Using this, the change of dose according to the opening and closing of the door and the installation of the shield was analyzed. Using this, we compared and analyzed the dose change according to the door opening and closing and the installation of the shield, and significance was verified through the SPSS ver. 24. Depending on whether the door was opened or closed, 11,215.35%, 159.0%, 101.9% increased in front of the door in the consol room, behind the wall and behind the lead glass. Depending on the installing of the shield, the 49.2%, 29.6%, 19.9%, 30.6% decrease in front of the door in the examination and consol room, behind the wall and lead glass. In addition, statistical analysis was showed that there were significant differences in both the results according to whether the door was opened or closed and shielding(p<.05). Close the door during radiography. However, when the door should be opened, it was confirmed that the dose rate were reduced by installing the shield. Therefore, to optimize radiation protection, it is recommended to install shields when opening the door.

• 대한방사선기술학회지:방사선기술과학
• /
• 제19권2호
• /
• pp.51-57
• /
• 1996

Radiography should be used judiciously and should not delay patients resuscitation. In the patient with emergency multiple trauma, three radiography should be obtained-cervical spine, anteroposterior(AP) chest, and AP pelvis. These examinations can be done in the resuscitation area, usually with a portable X-ray unit, but should not interrupt the resuscitation process. A retrospective study was carried on 157 emergency multiple trauma patients who were admitted to Yong Dong Severance Hospital from January, to December in 1995. I analyzed the types of X-ray examinations in emergency multiple trauma patients, and classified the patients by disoriented group of mentality. The results were as follows: 1. The subjects were 7.1%(157patients) of 2,208 trauma patients(7.3%) in total 30,085 emergency patients. 2. Male to female ratio was 2.57 : 1. The age distribution was highest from 31 years to 40 years(28.0% ). 3. The peak time of patient's entrance in emergency center was between 8 : 00 pm and 2 : 00 am(36.9%), and second peak time was between 2 : 00 pm and 8 : 00 pm (29.3%). 4. According to the injury type, traffic accident, motorcycle accident and falling down were 71.3%, 8.3% and 20.4% respectively. 5. According to the exposure rate of Computed Tomography, chest CT, cervical CT pelvis CT and brain CT were 39.5%, 24.2%, 69.4% and 51.6% respectively.

• 대한방사선기술학회지:방사선기술과학
• /
• 제37권3호
• /
• pp.169-175
• /
• 2014

2013년 국민건강보험심사평가원의 의료기관 데이터베이스에 따르면 1118개의 병.의원에 영상의학과가 개설되어있다. 이들 병원에는 CT, 투시촬영장치, 일반촬영장치와 같은 의료용 방사선 발생장치가 운영되고 있다. 이 중에서도 일반촬영장치는 가장 많은 병원에서 운영되고 있는 장비이다. 일반촬영장치의 경우 film-screen 장치에서 digital radiography 로 급격하게 변하고 있다. 하지만 그 촬영기법은 films-screen 기법을 그대로 사용하고 있어 디지털 장치의 맞는 촬영기법의 개발을 위한 전반적인 실태 조사가 필요하다. 이에 본 연구에서는 국내 의료기관의 일반촬영기법에 관한 조사를 시행하여 실제 병원에서 사용하고 있는 일반촬영기법의 기술적 항목에 대한 현황을 파악하여 보았다. 본 연구에서는 의료기관에서 일반적으로 사용되는 일반촬영기법 26개에 대한 촬영기법의 전국 단위 조사에서 흉부, 두부, 척추, 골반에 해당하는 검사에 대한 분석을 시행하였다.