Film Cassette의 세균 오염도와 소독에 관한 연구

권대철,정경모 최지원 대한방사선과학회(구 대한방사선기술학회) 2000 방사선기술과학 Vol.23 No.2

PACS에서 의료영상정보의 익명처리와 관련된 법의 연구

권대철 한국방사선학회 2022 한국방사선학회 논문지 Vol.16 No.5

The purpose of this study is to comply with the operation and management of medical image information in PACS, the necessity of anonymizing the patient's personal information and the management status of the medical image information related to the personal The purpose of this study was to raise, discuss, and suggest the need for unification and coherence of the law by studying the content of the issues related to information related laws. In order to utilize information related to medical image information, it is necessary to unify the “Medical Act” or the “Bioethics Act” for clear legal application and consider the legal system’s consistency. Since there is a possibility of conflict due to issues that are not yet established, systematic coherence of the law is required to find the basic common denominator for the utilization and use of medical image information and to harmonize the law. In addition, the necessity of enacting the “Medical Information Protection Act” that can be practically applied and easily practiced by medical personnel and managers in the clinical field so that sensitive matters of medical image information and personal information can be protected and managed in a specific and systematic way. 연구의 목적은 PACS에서 의료영상정보를 운영과 관리를 준수하고 환자의 개인정보를 익명처리하기 위한 필요성과 관리와 관련된「의료법」,「개인정보 보호법」과「생명윤리법」에서 의료영상정보의 개인정보 관련법의 쟁점에 대한 내용을 연구하여 법의 일원화와 정합성을 위한 필요성에 대해서 문제를 제기하고 논의하고 제안하고자 한다. 의료영상정보와 관련된 정보 활용하기 위해서는 법적으로 명확한 적용을 위해「의료법」혹은「생명윤리법」으로 일원화하고 법체계를 법의 정합성을 고려할 필요가 있다.「개인정보 보호법」및「생명윤리법」에서 일치하지 않은 쟁점들로 인하여 충돌할 가능성이 있어 의료영상정보의 활용 및 이용을 위한 기본적인 공통분모를 찾아내어 법의 조화를 이루는 법의 체계적인 정합성이 요구된다. 추가적으로 의료영상정보 및 개인정보의 민감할 사항을 구체적이고 체계적으로 보호하고 관리할 수 있도록 임상에서 의료인 및 관리자들이 현실적으로 법을 적용하고 용이하게 실천이 가능한「의료정보보호법」을 제정할 필요성을 고려하여 추진하는 것도 필요하다.

Measurement of Image Quality in CT Images Reconstructed with Different Kernels

권대철,장근조,이종웅,최지원,구은회,동경래,이재승,진계환,Sungbo Seo 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.58 No.2

This study measured the image quality obtained with different scanning and reconstruction kernels for computed tomography (CT) and sought methods for visualizing the abdominal and the bar phantoms. Our objective was to evaluate the image quality of spatial domain filtering as an alternative to additional image reconstruction using different kernels in CT. CT images were obtained using a 16-multidetector CT (MDCT) scanner and were reconstructed with various reconstruction kernels. Kernels were grouped as abdominal kernels. Image data sets were reconstructed using a very smooth (B10), smooth (B20), medium smooth (B30), medium (B40), medium sharp (B50), sharp (B60), very sharp (B70), and dedicated, ultra-sharp (B80) reconstruction kernel. The B20 and the B30 kernels provided better peak signal-to-noise ratio (PSNR), less root mean square error (RMSE), maximum absolute error (MAE), and reconstructed convolution kernels comparable to other kernels used as reconstruction kernels. The increase in the diagnostic accuracy of CT images obtained using the abdominal B20 and B30 kernels may be controlled by adjusting the various CT algorithms, to take into account the kernels of the CT algorithm undergoing the examination.

Use of a GM Counter to Measure the Half-life of Ba-137m Generated by Using an Isotope Generator

권대철,최지원,동경래,정운관,송현제,김영재 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.65 No.4

A Cs-137/Ba-137m isotope generator is used to demonstrate the properties of radioactive decay. In this experiment, we investigate and verify the random behavior of radioactive decay anddetermine the half-life of a radioactive isotope. The half-life of a radioisotope is measured in thisexperiment. The purpose of this experiment is to determine the half-life of Ba-137m by using severalmethods and to determine the percent error for each determination. Ba-137m decays by gammaemission (662 keV) with a half-life of 2.6 minutes to the stable Ba-137 element. During elution,Ba-137m is selectively “milked” from the generator, leaving behind the Cs-137 parent. Each generatoris supplied with 250 mL of an eluting solution (0.9% NaCl in 0.04M HCl). A Geiger counterinterfaced with a computer is used to acquire and record the activity at set time intervals. Thehalf-life of the radioactive isotope Ba-137m is determined by measuring the activity of a sampleas it decays. The half-life of Ba-137m, which has been extracted from the radioisotope Cs-137, isdetected by using AktivLab. The theoretical half-life of Ba-137m is approximately 2.56 minutes,and the result from the experiment is 2.6 minutes. In summary, a radioisotope generator containingCs-137 produces Ba-137m, which is extracted in a solution. The Ba-137m has a half-life of about2.6 minutes as measured during this research.

G-M 계수관과 137Cs 선원을 이용한 납 반가층의 실험적 연구

권대철,동경래 (사)한국방사선산업학회 2016 방사선산업학회지 Vol.10 No.3

HVL (half-value layer) of lead was measured experimentally using a lead and 137Cs (370 kBq) source and a G-M counter in which is used a lot of material for shielding HVL measured. 137Cs in holder to 10 cm and start measuring the radiation. Continue addition of lead of the lead thickness of 1 mm one by one to continue the measurement. By measuring four times the natural radiation of 100 seconds and records the count value and the average rate to be displayed on the meter. Background radiation was a 4 times a count rate and the average 108 (100 s-1) as a result of measuring the average measurement, the standard deviation was determined to be 1.08 (s-1). An increase in the thickness of lead initial count rate starting from 920 (N) count rate is decreased with increase in the thickness of lead. Net counting rate, starting with the initial 8.12 (s-1) showed a decrease with increasing thickness, the standard deviation of the results was decreased from 0.303 (s-1) to 0.196 (s-1). Net counting rate is reduced to obtain the result that each half thickness of nappan about 7 mm. Was reduced similarly to the exponential function graph correlation coefficient (R2) was found to be 0.9869. Half-value layer which is the initial net counting rate 7.514 (s-1) is a half the 7 mm to 3.757 (s-1). In conclusion, it was confirmed the theoretical HVL of lead 7.19 mm and experimentally measured results matched the measured HVL 7 mm.

공공데이터를 활용한 영농일지 작성 시스템

권대철,김상근,김능회 한국인터넷방송통신학회 2022 한국인터넷방송통신학회 논문지 Vol.22 No.6

As public data opened its doors in line with the era of the 4th Industrial Revolution, agricultural public data also increased. Currently, the majority of farmers are writing farming diaries due to eco-friendly certification and basic public interest direct payment projects. However, it is a difficult task for busy farmhouses in the aging agricultural community to write farming diaries. Therefore, there have been cases where farming diaries have been filled out on behalf of the farmhouses. However, one may get disadvantaged in terms of receiving eco-friendly certification and public interest direct payment projects. In succession, this paper proposes a system to conveniently write farming diaries by checking the farming diary data stored in the server via categories of crops and dates and finding farming diary public data suitable for the user to automatically fill out the diary.

CT검사에서 조영제의 혈관외유출에 의한 목 및 흉부 손상의 3차원 재구성 영상

권대철,유병규,장근조,이종석 대한방사선과학회 2007 방사선기술과학 Vol.30 No.3

전산화단층촬영에서 조영제를 자동주입기로 주입하는 과정에서 발생하는 혈관외유출은 조직의 괴사 및 손상의 원인이 되고 있다. 대량의 혈관외유출은 구획증후군으로 발전하여 근막절개술을 시행하는 경우가 발생한다. 혈관외유출이 발생한 환자를 대상으로 혈관외유출 범위 및 부위 정도를 평가하기 위해 CT 검사에서 경정맥에 조영제을 주입하는 과정에서 혈관외유출이 발생한 환자를 대상으로 하였다. 조영제에 의한 혈관외유출 범위 및 손상을 확인하기 조영제 주입부위의 목 및 가슴의 부위를 MDCT를 이용하여 스캔하였다. 경정맥 주사부위의 혈관외유출부위를 MPR, MIP와 볼륨 렌더링의 3차원영상을 3D 프로그램을 이용하여 묘출하였다. 3차원 재구성 영상은 높은 해상력과 정확도를 제공하여 혈관외유출 범위 및 부위를 확인 하여, 환자의 예방의 필요성 및 사후 조치 및 적절한 치료와 수술 계획에 유용하게 이용될 것으로 기대된다.

An Overall Stem Effect, including Stem Leakage and Stem Scatter, for a TM30013 Farmer-type Chamber

권대철,이재승,구은회,김문집,정재은,동경래,정운관,임인철,유윤식 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.58 No.6

The stem effect is a leakage current generated when the chamber stem is included in the radiation field size. Such an effect can be divided into stem leakage and stem scatter. When a chamber is calibrated in air, the chamber response is likely to be affected by the photons scattered from the chamber stem. These interactions contribute to the apparent measured exposure. We calculated the overall stem effect correction factor that was caused by the metal stem of the ionization chamber. We measured the stem effect of a Farmer-type ionization chamber that had recently been in use for exposure dose measurements. In addition, we calculated and compared the ratios of stem leakage and stem scatter to the overall stem effect. We measured an overall stem effect, including the stem leakage and the scatter of PTW model TM 30013 (vented to air, sensitive volume 0.6 cm^3) Farmer chamber, in the exposure measurement. We measured the dependences of the stem scatter (k_(sem.scatter)) and the stem leakage (k_(sem.leak)) on the length of chamber stem exposure when measuring the exposure dose of high-energy X-rays generated by a linear accelerator (LINAC). Electrons ejected from the metal stem were collected by the central electrode, increased to a maximum and then decreased. Most of the overall stem effect was caused by stem scatter and was determined to within 4% according to the length of the stem exposed in repeated measurements of with various radiation fields.

대퇴골 전염각 측정을 위한 수 작업 방법과 Image Viewer 방법과의 비교 연구

권대철,박범,Gwon, Dae-Cheol,Park, Beom 대한인간공학회 2001 大韓人間工學會誌 Vol.20 No.3

The measurement of the fermoral anteversion is an important factor in the practice of orthopedic surgery. The anteversion is measured by means of the axis of head and neck of the femur. In this study. widely used computed tomography method of measuring anteversion was tested on femoral necks of patients. Measurement by the manual method and image viewer of computed tomography to determine the anteversion of femoral head were carried out on both femurs. In January and February 2001, 30 patients 3 to 6 years of age were randomly selected from Seoul National University Hospital. the purpose of this paper was to introduce a new method to measure femoral anteversion angle utilizing image viewer program. This new method was more accurate and convenient than the conventional manual method. No significant difference was observed between the manual method and the image viewer measurement of femoral anteversion. In conclusion, image viewer program was statistically more reliable in determining the angle of the fermoral anteversion.

PACS Image Viewer에서의 CT와 MR 영상의 대퇴골 전염각 비교 연구

권대철,양성환,박범 대한의료정보학회 2002 Healthcare Informatics Research Vol.8 No.4

CT and MR have been used successfully to estimate the femoral anteversion angle. It is measured by means of the axis of head and neck of the femur and the knee axis. At the present time, widely used computed tomography method of measuring anteversion on femoral necks of patients. In this study, femoral anteversion angles in 36 years old human adult femur was determined by CT and MR imaging and the measurements compared. Measurement by the manual method and image viewer of computed tomography to determine the anteversion of femoral head were carried out on both femurs. On CT, the mean angle for adults was 20.1°. On MR imaging, the mean angle for adults was 20.4°. The correlation coefficient between angles determined by CT and MRI scan(r=.80). The femoral anteversion angles by MR imaging exceeded those obtained by CT. No significant difference was observed between the CT and MR imaging. MR imaging is recommended for prospective planning very usefulness in the measured the angle of the femoral anteversion.