Accuracy of radiographers in Fiji in interpreting adult chest X-ray images

IntroductionThe idea of radiographer image interpretation has not been fully explored in Fiji despite the great shortage of radiologists in the country. This is a feasibility study of radiographer image interpretation aimed at assessing the accuracy of radiographers in interpreting adult chest X-ray images at the Colonial War Memorial Hospital (CWMH) in Fiji.MethodsForty PA chest X-ray images were interpreted in terms of correctly commenting on the presence/ absence of pathology, the name of the pathology, and the location of the pathology on the data sheets by the CWMH diagnostic radiographers (n = 14). The radiographers were grouped according to their years of work experience (≤ 5 vs > 5) and the Mann Whitney U test on a two-tailed p-value of 0.05 was used to compare this grouping.ResultsThe data analysis was conducted using the Statistical Package for Social Sciences (SPSS) v.25 and Microsoft Excel. The diagnostic performance of all radiographers in terms of triaging normal and abnormal in the images shows sensitivity ranging from 71.4 to 100%, with specificity ranging from 47.4 to 100%. The mean sensitivity, specificity, and the overall accuracy of radiographers in triaging normal and abnormal on the images were 89.5%, 72.9%, and 81.6%, respectively. The mean accuracy in naming the pathology was 33.6% and the location sensitivity was 45.7%. There was no statistically significant difference in results between the radiographers’ years of experience.ConclusionWithout any formal qualification, training, and practice, the current results suggest that the cohort of radiographers can perform normal/abnormal triage of CXRs within a test setting. With a significant reduction in the radiographers’ accuracy in terms of naming and locating the abnormality, the study results do not support image interpretation by the radiographers at this stage.Implications for practiceThis feasibility study provides baseline information about the accuracy of image interpretation by diagnostic radiographers at CWMH and provides a platform for further research in image interpretation in Fiji.     

高能光源储存环及同步加速器屏蔽计算与探讨

目的验证和探讨在高能同步辐射光源辐射屏蔽计算中半经验公式和蒙特卡罗模拟方法的一致性和适用性。方法分别采用半经验公式和蒙特卡罗模拟独立计算单电子打靶时屏蔽体外产生的周围剂量当量。结果Jenkins半经验公式计算结果与蒙特卡罗模拟结果比值范围为111%~153%,Sakano半经验公式计算结果与蒙特卡罗模拟结果比值为201%。结论对单一屏蔽材料,半经验公式可简单、保守地完成对高能电子加速器的屏蔽计算。对于多种屏蔽材料,宜采用蒙特卡罗模拟方法。     

Assessment of the radiological safety of a Genoray portable dental X-ray unit

Objectives:

The portable dental radiographic systems are generally used in emergency situations (e.g. during natural disasters) for disabled/aged patients and in patient rooms. This study assesses the output exposure of a portable dental radiographic system measured using thermoluminescent dosemeters (TLDs).

Methods:

Occupational exposure of the operator was determined when the portable dental unit was used for mandibular and maxillary teeth exposure.

Results:

The doses of some critical organs of an operator were measured using TLDs implanted within the Rando phantom.

Conclusions:

Considering the annual organ dose limits, the eye lens dose limit is the main factor determining the frequency of system application.     

水中总α和总β放射性分析的质量控制

目的 为了提高水中总放射性检测的精密度和正确度,对检测项目系统开展方法验证和质量控制,提升实验室放射卫生和环境监测水平。方法 采用总α分析的厚源法和总β分析的薄样法,对实际样品开展多次分析,计算检测方法的精密度;通过加标回收率实验和2019年全国放射卫生比对样品测试,进行方法的正确度分析。结果 精密度实验中,相同样品多次分析的总α、总β结果相对标准偏差分别为23%和13%;3次加标回收率实验结果分别为103.1%、103.5%和105.8%;2019年全国水中总α、总β比对样品测量结果,与参考值的相对误差分别为0.92%和9.4%,体现了较高的正确度。结论 方法验证和质量控制工作中的相对标准偏差、回收率、相对误差均在标准限制范围之内。这项工作系统介绍了水中总α、总β放射性检测可能引入误差的主要环节,进一步提高了放射卫生和环境放射性监测的水平。     

A validation of computational phantoms from photographic images for patient-tailored whole body counting

This study attempted to validate a new method for patient-tailored efficiency calibration. Digital calibration with Monte Carlo simulations was used to substitute the lack of precision limitation due to the limited number of experimental phantoms in whole body counting calibration for internal dosimetry. The validity of this approach was examined by comparing the simulation results to the measured values from actual measurements using family BOMAB phantoms. The computational voxel phantoms were constructed by a reconstruction technique using AP and lateral photographic images of the BOMAB phantoms, instead of using the given specifications provided with BOMAB phantoms. Although discrepancies to a certain degree between the computational simulation and measured efficiencies do exist, the results support the new approach of being an alternative to family BOMAB phantoms.     

Vitamin D metabolism impairment in the rat’s offspring following maternal exposure to <Superscript>137</Superscript>cesium

Previous works clearly showed that chronic contamination by ¹³⁷cesium alters vitamin D metabolism. Since children are known to be a high-risk group for vitamin D metabolism disorders, effects of ¹³⁷Cs on vitamin D biosynthetic pathway were investigated in newborn rats. The experiments were performed in 21-day-old male offspring of dams exposed to ¹³⁷Cs in their drinking water at a dose of 6,500 Bq/l (150 Bq/rat/day) during the lactation period. Significant modifications of blood calcium (−7%, P < 0.05), phosphate (+80%, P < 0.01) and osteocalcin (−25%, P < 0.05) levels were observed in contaminated offspring, associated with an increase of blood vitamin D₃ (+25%, P < 0.01). Besides, decreased expression levels of cyp2r1 and cyp27b1 (−26 and −39%, respectively, P < 0.01) were measured in liver and kidney suggesting a physiological adaptation in response to the rise in vitamin D level. Expressions of vdr, ecac1, cabp-d28k, ecac2 and cabp-9k involved in renal and intestinal calcium transport were unaffected. Altogether, these data show that early exposure to post-accidental doses of ¹³⁷Cs induces the alteration of vitamin D metabolism, associated with a dysregulation of mineral homeostasis.