修车大队一品楼qm论坛51一品茶楼论坛,栖凤楼品茶全国楼凤app软件 ,栖凤阁全国论坛入口,广州百花丛bhc论坛杭州百花坊妃子阁

oe1(光电查) - 科学论文

15 条数据
?? 中文(中国)
  • Radiation exposure during direct versus indirect image acquisition during fluoroscopy-controlled internal fixation of a hip fracture: Results of a randomized controlled trial

    摘要: Background: Intra-operative image acquisition can be obtained indirectly (via verbal request to a technician) or directly (executed at the tableside, by a surgeon stepping on a foot pedal). Direct image acquisition could reduce the exposure time and thus the risk of radiation damage. The aim of this randomized controlled trial was to compare direct surgeon-controlled fluoroscopy with indirect technician-operated fluoroscopy during internal fixation of a hip fracture. Methods: From March 5, 2014 to August 19, 2015, 100 patients who had sustained a hip fracture that required internal fixation were enrolled. Patients were randomized between direct surgeon-controlled image acquisition using a foot pedal (n = 52) and indirect image acquisition by a radiology technician (n = 48). The primary outcome measure was the radiation exposure time; secondary outcome measures were the associated effective radiation dose and the dose area product. (DAP) Results: A total of 96 patients (with a median age of 84 years) were enrolled in this study. Eighty-nine (93%) patients had a pertrochanteric fracture. No statistically significant differences between direct image acquisition and indirect image acquisition were found for overall radiation time, total radiation dose or DAP for the total population. When adjusted for potential confounders, a difference in overall radiation time of 18.50 s (95% CI 2.19; 34.81, p = 0.027) was found in favour of indirect image acquisition. Conclusion: This study showed statistically significantly lower radiation duration using indirect fluoroscopy for the total population and the pertrochanteric fracture subgroup when adjusted for several confounders. No significant effect on radiation dose and DAP was found.

    关键词: Radiation dosage,Radiation protection,Hip fractures,Fluoroscopy,Femoral fractures

    更新于2025-09-11 14:15:04

  • PATIENT DOSE IN DIGITAL RADIOGRAPHY UTILISING BMI CLASSIFICATION

    摘要: Dose audit is important towards optimisation of patients’ radiation protection in diagnostic radiography. In this study, the effect of the body mass index (BMI) on radiation dose received by 1869 adult patients undergoing chest, abdomen, lumbar spine, kidneys and urinary bladder (KUB) and pelvis radiography in an X-ray room with a digital radiography system was investigated. Patients were categorised into three groups (normal, overweight and obese) based on the BMI values. The patients’ entrance surface air kerma (ESAK) and the effective dose (ED) were calculated based on the X-ray tube output, exposure parameters and technical data, as well as utilising appropriate conversion coefficients of the recorded kerma area product (KAP) values. The local diagnostic reference levels (LDRLs) were established at the 75th percentile of the distribution of ESAK and KAP values. Statistically, a significant increase was found in ESAK, KAP and ED values, for all examinations, both for overweight and obese patients compared to normal patients (Mann–Whitney test, p < 0.0001). Regarding the gender of the patients, a statistically significant increase was found in the dose values for male patients compared to female patients, except for the chest LAT examinations (Mann–Whitney test, p = 0.06). The percentage increase for chest PA, chest LAT, abdomen AP, lumbar spine AP, lumbar spine LAT, pelvis AP and KUB AP in overweight patients was 75%, 100%, 136%, 130%, 70%, 66% and 174% for median ESAK, 67%, 81%, 135%, 134%, 85%, 63% and 172% for median KAP, as well as 89%, 54%, 146%, 138%, 82%, 57% and 183% for median ED values, respectively. For obese patients, the corresponding increases were 200%, 186%, 459%, 345%, 203%, 150% and 785% for median ESAK, 200%, 185%, 423%, 357%, 227%, 142% and 597% for median KAP, as well as 222%, 156%, 446%, 363%, 218%, 136% and 625% for median ED. The corresponding LDRLs for overweight patients were 0.17 mGy, 1.21 mGy, 3.74 mGy, 7.70 mGy, 7.99 mGy, 4.07mGy, 5.03 mGy and 0.13 Gy cm2, 0.69 Gy cm2, 2.35 Gy cm2, 2.10 Gy cm2, 2.59 Gy cm2, 2.13 Gy cm2, 2.49 Gy cm2 in terms of ESAK and KAP values, respectively, while in the case of obese patients were 0.28 mGy, 1.82 mGy, 7.26 mGy, 15.10 mGy, 13.86 mGy, 6.89 mGy, 13.40 mGy and 0.21 Gy cm2, 1.10 Gy cm2, 4.68 Gy cm2, 4.01 Gy cm2, 4.80 Gy cm2, 3.27 Gy cm2, 6.02 Gy cm2, respectively. It can be concluded that overweight and obese patients received a significantly increased radiation dose. Careful adjustment of imaging protocols is needed for these patients to reduce patient dose, while keeping the image quality at an acceptable level. Additional studies need to be conducted for these patient groups, that could further contribute to the development of radiation protection culture in diagnostic radiography.

    关键词: BMI,diagnostic reference levels,patient dose,radiation protection,digital radiography

    更新于2025-09-10 09:29:36

  • Automated and observer based light field indicator edge evaluation in diagnostic X-ray equipment

    摘要: Introduction: To analyze edge detection and optical contrast calculation of light field-indicators used in X-ray via automated- and observer-based methods, and comparison with current standard approaches, which do not give exact definition for light field edge determination. Methods: Automated light sensor array was used to measure the penumbra zone of the edge in the standard X-ray equipment, while trained and na?ve human observers were asked to mark the light field edge according to their own determination. Different interpretations of the contrast were then calculated and compared. Results: In contrast to automated measurements of edge definition and detection, measurements by human observers showed large inter-observer variation independent of their training with X-ray equipment. Different contrast calculations considering the different edge definitions gave very different contrast values. Conclusion: As the main conclusion, we propose a more exact edge definition of the X-ray light field, corresponding well to the average human observer’s edge determination. The new edge definition method with automated systems would reduce human variability in edge determination. Such errors could potentially affect the approval of X-ray equipment, and also increase the radiation dose. The automated measurement based on human observers’ edge definition and the corresponding contrast calculation may lead to a more precise light field calibration, which enables reduced irradiation doses on radiology patients.

    关键词: X-ray equipment type test,Radiation protection,Edge determination,Light field indicator,Diagnostic X-ray

    更新于2025-09-10 09:29:36

  • Evaluation of radiation protection conditions in intraoral radiology

    摘要: Introduction: The dental radiology represents about 20% of human exposure to radiation in radio diagnostic. Although the doses practiced in intraoral dentistry are considered low, they should not be ignored due to the volume of the performed procedures. This study presents the radiation protection conditions for intraoral radiology in Curitiba - PR. Methods: Data was collected through a quantitative field research of a descriptive nature during the period between September of 2013 and December of 2014. The survey sample consisted of 97 dentists and 130 intraoral equipments. The data related to the equipments was collected using structured questions and quality control evaluations. The evaluations of the entrance skin dose, the size of the radiation field and the total filtration were performed with dosimetry kits provided and evaluated by IRD/CNEN. The exposure time and voltage were measured using noninvasive detectors. The occupational dose was verified by thermoluminescent dosimeters. The existence of personal protection equipment, the type of image processing and knowledge of dentists about radiation protection were verified through the application of a questionnaire. Results: Among the survey’s results, it is important to emphasize that 90% of the evaluated equipments do not meet all the requirements of the Brazilian radiation protection standards. Conclusion: The lack of knowledge about radiation protection, the poor operating conditions of the equipments, and the image processing through visual method are mainly responsible for the unnecessary exposure of patients to ionizing radiation.

    关键词: Radiation protection,Intraoral radiology,Quality control in radiology

    更新于2025-09-09 09:28:46

  • The future SwissFEL facility – challenges from a radiation protection point of view

    摘要: The Swiss Free Electron Laser is a new large-scale facility currently under construction at the Paul Scherrer Institute. Accessible areas surrounding the 720 m long accelerator tunnel, together with the pulsed time structure of the primary beam, lead to new challenges for ensuring that the radiation level in these areas remains in compliance with the legal constraints. For this purpose an online survey system based on the monitoring of the ambient dose rate arising from neutrons inside of the accelerator tunnel and opportunely calibrated to indicate the total dose rate outside of the tunnel, will be installed. The presented study provides a conceptual overview of this system, its underlying assumptions and measurements so far performed to validate its concept.

    关键词: online survey system,neutrons,ambient dose rate,accelerator tunnel,SwissFEL,radiation protection

    更新于2025-09-09 09:28:46