In order to improve the diagnostic quality of X-ray device and to promote the implementation of radiation protection in accordance to the ICRU definition and ICRP classification standards for measuring radiation harm to human body, we have made a number of tests, including the kinetic energy released by ionizing air, the Half-value layer, the output dose coincidence, the High contrast resolution, the Consistency between visual light field and project X-ray field, and the Focus of X-ray tube. We have also analysed the measured data and results. The tests were conducted on the XEB150L-20 made by Shimadzu Co. in the middle of 1990s.
Quality Control ; Radiation Dosage ; Radiation Monitoring ; methods ; Radiation Protection ; methods ; Radiography ; instrumentation ; Radiometry ; methods

OBJECTIVETo explore the dose-length product calibration method for pencil ionization chamber in cobalt beams.

METHODSThe PTW TM30009 ionization chamber was placed into the central hole of T40017 head phantom and irradiated 60 s in 20 cm x 20 cm cobalt beam. The charge was collected with UNIDOS electrometer. Absorbed doses were measured with TM30013 0.6 mL farmer-type chamber under the same condition. The CT chamber calibration factor was expressed in dose-length product. Dose linearity and spatial response were also investigated.

RESULTSThe calibration factor in dose-length product was derived from measured data. Dose linearity and spatial response were good in cobalt beams.

CONCLUSIONIt is feasible to calibrate the CT chamber in cobalt beams for patient dose evaluation in MVCT.

Calibration ; Radiation Monitoring ; methods ; Radiation, Ionizing ; Radiometry ; Tomography, X-Ray Computed ; instrumentation

PURPOSE: The current study investigates the feasibility of a platform for a nationwide dose monitoring system for dental radiography. The essential elements for an unerring system are also assessed. MATERIALS AND METHODS: An intraoral radiographic machine with 14 X-ray generators and five sensors, 45 panoramic radiographic machines, and 23 cone-beam computed tomography (CBCT) models used in Korean dental clinics were surveyed to investigate the type of dose report. A main server for storing the dose data from each radiographic machine was prepared. The dose report transfer pathways from the radiographic machine to the main sever were constructed. An effective dose calculation method was created based on the machine specifications and the exposure parameters of three intraoral radiographic machines, five panoramic radiographic machines, and four CBCTs. A viewing system was developed for both dentists and patients to view the calculated effective dose. Each procedure and the main server were integrated into one system. RESULTS: The dose data from each type of radiographic machine was successfully transferred to the main server and converted into an effective dose. The effective dose stored in the main server is automatically connected to a viewing program for dentist and patient access. CONCLUSION: A patient radiation dose monitoring system is feasible for dental clinics. Future research in cooperation with clinicians, industry, and radiologists is needed to ensure format convertibility for an efficient dose monitoring system to monitor unexpected radiation dose.
Cone-Beam Computed Tomography ; Dental Clinics ; Dentists ; Humans ; Methods ; Radiation Dosage ; Radiation Monitoring ; Radiography ; Radiography, Dental*

Objective: To investigate the individual external dose level of some interventional radiology staffs from 2016 to 2020 in Tianjin City. Methods: All 2068 interventional radiology staffs who were included in the work of the Radiation Monitoring Project from 2016 to 2020 were selected as study subjects in March 2021. The individual dose monitoring results of interventional radiology staffs of different ages, working years, time and medical institutions were analyzed. Results: Among 2068 interventional radiology workers, 1406 (67.99%) were male and 662 (32.01%) were female. The age was 44.6 (39.2, 50.3) years, and the working years was 10.5 (4.3, 14.6) years. The annual effective doses per capita of 40-49 age group and ≥50 age group were higher than that of 30-39 age group (P<0.05) . The annual effective dose per capita of 5-9 working years was higher than that of <5 working years, and the annual effective dose per capita of 10-29 working years was higher than that of 5-9 working years (P<0.05) . The median per capita annual effective dose of the interventional radiology staffs was 0.164 mSv. There were 1976 interventional radiology staffs with an annual effective dose of <0.50 mSv/a (95.6%) . The collective dose distribution ration SR(0.5) was 41.1%. The difference of effective dose per capita in each year was statistically significant (H=19.23, P<0.05) . The per capita annual effective dose of interventional radiology staffs in tertiary medical institutions was higher than that in secondary medical institutions, and the difference was statistically significant (P<0.05) . Conclusion: The personal dose of interventional radiology staffs in Tianjin City is at a low level. It is necessary to emphasize the radiation hazard protection of interventional radiology staffs in tertiary medical institutions, 40-49 years old, ≥50 years old age groups and 5-9, 10-29 working years groups.
Adult ; Female ; Humans ; Male ; Middle Aged ; Occupational Exposure/prevention & control* ; Radiation Dosage ; Radiation Monitoring/methods* ; Radiation Protection ; Radiology, Interventional

BACKGROUND/AIMS: ERCP using fluoroscopy should be practiced with an adequate radiation protection. However, the awareness of gastrointestinal endoscopists to radiation protection was considered insufficient. In Korea, a country with a rapid increase the number of ERCP procedures, there is no data about radiation protection practices for gastrointestinal endoscopists. The purpose of this study was to investigate current clinical practices and the awareness on radiation protection in ERCP performing physicians in Korea. METHODS: An anonymous questionnaire regarding radiation protection practices was mailed to 100 members of Korean Pancreatobiliary Association who was porforming ERCP. The questionnaire included ERCP volume of each endoscopist, use of protection devices such as apron, thyroid shield, lead glasses and any mobile shield for scattered radiation, and whether they monitored their own radiation exposure dosage. RESULTS: All respondents wore lead aprons during ERCP. While 52.5% of endoscopists answered that they always wear thyroid guards, 26.9% rarely or never wore it. Only 14% wore lead glasses during the procedure and 69% never wore it. The preparation rates of mobile shields or lead curtains were only 14% and 24%, respectively. Only 10% of endoscopists attached an X-ray badge and 66.7% never used it. Moreover, 75% of endoscopists responded that they did not monitor their own exposure dose to radiation during ERCP. CONCLUSIONS: The lack of radiation protection of ERCP endoscopists in Korea was seemed serious. Awareness of radiation hazard should be more concerned and educated in parallel with the preparation of radiation protection equipments.
*Cholangiopancreatography, Endoscopic Retrograde ; Eye Protective Devices ; Female ; Hospitals ; Humans ; Male ; Occupational Exposure/*prevention & control ; Questionnaires ; Radiation Monitoring ; Radiation Protection/*methods ; Thyroid Gland/radiation effects

BACKGROUND/AIMS: The increasing use of diagnostic and therapeutic endoscopic retrograde cholangiopancreatography (ERCP) calls for greater consideration of radiation exposure risk to endoscopists and assistants, and emphasizes the proper system of radiation protection. This study was designed to assess the effect of a newly developed, self-designed, protective lead shield. METHODS: A curtain-shaped protective shield composed of seven movable lead plates was developed, each with the following dimensions: depth, 0.1 cm; width, 15 cm; length, 70 cm. The curtain-shaped protective shield was designed to be located between the patient and the endoscopist. Twenty-nine patients (11 men and 18 women) undergoing ERCP between January 2010 and March 2010 were selected for this study. The dose of radiation exposure was recorded with or without the protective lead shield at the level of the head, chest, and pelvis. The measurement was made at 50 cm and 150 cm from the radiation source. RESULTS: The mean patient age was 64 years. The mean patient height and weight was 161.7+/-6.9 cm and 58.9+/-9.9 kg, respectively. The mean body mass index (BMI) was 22.5+/-3.0 kg/m2. Endoscopists received 1522.2+/-537.0 mR/hr without the protective lead shield. At the same distance, radiation exposure was significantly reduced to 68.8+/-88.0 mR/hr with the protective lead shield (p-value<0.0001). The radiation exposure to endoscopists and assistants was significantly reduced by the use of a protective lead shield (p value<0.0001). The amount of radiation exposure during ERCP was related to the patient's BMI (r=0.749, p=0.001). CONCLUSIONS: This self-designed, protective lead shield is effective in protecting endoscopists and assistants from radiation exposure.
Adult ; Aged ; Body Mass Index ; Cholangiopancreatography, Endoscopic Retrograde/*adverse effects ; Common Bile Duct Diseases/diagnosis/therapy ; Female ; Humans ; Male ; Middle Aged ; Radiation Dosage ; Radiation Injuries/*prevention & control ; *Radiation Monitoring/methods ; Radiation Protection/*methods

Electromagnetic Fields ; adverse effects ; Environmental Exposure ; adverse effects ; Humans ; Occupational Exposure ; adverse effects ; Radiation Monitoring ; methods ; Risk Assessment

Animals ; Antibodies, Monoclonal ; pharmacokinetics ; Iodine Radioisotopes ; pharmacokinetics ; Leukocyte Common Antigens ; immunology ; Male ; Mice ; Radiation Monitoring ; methods ; Rats ; Tissue Distribution

The purpose of this study was to compare the dose distribution of intensity-modulated radiotherapy (IMRT) in 7 and 5 fields as well as 3-D conformal radiotherapy (3D-CRT) plans for gastric cancer using dosimetric analysis. In 15 patients with gastric cancer after D1 resection, dosimetric parameters for IMRT (7 and 5 fields) and 3D-CRT were calculated with a total dose of 45 Gy (1.8 Gy/day). These parameters included the conformal index (CI), homogeneity index (HI), maximum dose spot for the planned target volume (PTV), dose-volume histogram (DVH) and dose distribution in the organs at risk (OAR), mean dose (Dmean), maximal dose (Dmax) in the spinal cord, percentage of the normal liver volume receiving more than 30 Gy (V30) and percentage of the normal kidney volume receiving more than 20 Gy (V20). IMRT (7 and 5 fields) and 3D-CRT achieved the PTV coverage. However, IMRT presented significantly higher CI and HI values and lower maximum dose spot distribution than 3D-CRT (P=0.001). For dose distribution of OAR, IMRT had a significantly lower Dmean and Dmax in spinal cord than 3D-CRT (P=0.009). There was no obvious difference in V30 of liver and V20 of kidney between IMRT and 3D-CRT, but 5-field IMRT showed lower Dmean in the normal liver than other two plans (P=0.001). IMRT revealed favorable tumor coverage as compared to 3D-CRT and IMRT plans. Specifically, 5-field IMRT plan was superior to 3D-CRT in protecting the spinal cord and liver, but this superiority was not observed in the kidney. Further studies are needed to compare differences among the three approaches.
Combined Modality Therapy ; Female ; Humans ; Kidney ; radiation effects ; Liver ; radiation effects ; Male ; Middle Aged ; Postoperative Period ; Radiation Injuries ; diagnosis ; prevention & control ; Radiation Monitoring ; methods ; Radiometry ; methods ; Radiotherapy Dosage ; Radiotherapy Planning, Computer-Assisted ; methods ; Radiotherapy, Conformal ; methods ; Radiotherapy, Intensity-Modulated ; methods ; Spine ; radiation effects ; Stomach Neoplasms ; radiotherapy ; surgery

OBJECTIVESTo investigate intensity of extremely low frequency magnetic field (ELFMF) emitted from cathode-ray tubes (CRT) of monitors in various directions and to find ways to avoid its influence.

METHODSTwo hundred CRT monitors and 10 monitors with liquid-crystal display (LCD) were selected. Their ELFMF was detected for three times in front of the monitor at an interval of every 5 cm from 0 cm to 50 cm, as well as at various directions from the monitor.

RESULTSIntensity of ELFMF significantly attenuated at regular operating position (30 - 40 cm) from 0 cm to 50 cm in front of both 38 cm and 43 cm CRT monitors (P < 0.05). Intensity exceeded 0.4 microT both within 15 cm and 10 cm in front of 38 cm and 43 cm monitors. The highest intensity was found at the upright top position of both kinds of monitors, 9.54 microT for 38 cm monitor and 6.38 microT for 43 cm one, respectively.

CONCLUSIONSIt is suggested to keep away from monitor screen as possible when operating a computer, to reduce unnecessary operation in front of a monitor screen, and to shorten operating time. To avoid more hazards from interactive interference between computers, it is necessary to increase distance between monitors.

Computers ; Electromagnetic Fields ; adverse effects ; Environmental Exposure ; adverse effects ; Equipment Safety ; Humans ; Occupational Exposure ; adverse effects ; Radiation Monitoring ; methods ; Risk Assessment