光学表面监测系统与CBCT确定左侧乳腺癌深吸气屏气放疗误差的比较

目的 建立本单位应用光学表面监测系统(OSMS)门控技术在左侧乳腺癌深吸气屏气(DIBH)放疗的基本流程,比较应用OSMS与CBCT确定左侧乳腺癌DIBH放疗摆位误差的一致性。方法 20例左侧乳腺癌患者采用DIBH方法治疗,OSMS与模拟定位DIBH体表外轮廓配准,CBCT扫描与模拟定位CT配准各记录得到误差数据,数据包括左右(x)、上下(y)、前后(z)方向平移误差和旋转误差Rx、Ry、Rz。采用Pearson法分析两者相关性,Bland-Altman法检验两者一致性。结果 两种方法呈正相关,x、y、z方向平移误差以及Rx、Ry、Rz方向旋转误差的相关系数分别为0.84、0.74、0.84、0.65、0.41、0.54(P<0.01),95%CI值分别为-0.37~0.42 cm、-0.39~0.41 cm、-0.29~0.49cm和-2.9°~1.4°、-2.6°~1.4°、-2.4°~2.5°,均<5mm和3°。20例左侧乳腺癌DIBH放疗患者系统误差<0.18cm,随机误差<0.24cm。结论 左侧乳腺癌DIBH放疗中应用OSMS与CBCT两种方式确定与模拟定位状态误差具有一致性,CBCT图像引导基础上使用无辐射的OSMS验证位置信息是安全可靠的。     

Organ-based tube current modulation in chest CT. A comparison of three vendors

IntroductionOrgan-based tube current modulation (OBTCM) is designed for anterior dose reduction in Computed Tomography (CT). The purpose was to assess dose reduction capability in chest CT using three organ dose modulation systems at different kVp settings. Furthermore, noise, diagnostic image quality and tumour detection was assessed.MethodsA Lungman phantom was scanned with and without OBTCM at 80–135/140 kVp using three CT scanners; Canon Aquillion Prime, GE Revolution CT and Siemens Somatom Flash. Thermo-luminescent dosimeters were attached to the phantom surface and all scans were repeated five times. Image noise was measured in three ROIs at the level of the carina. Three observers visually scored the images using a fivestep scale. A Wilcoxon Signed-Rank test was used for statistical analysis of differences.ResultsUsing the GE revolution CT scanner, dose reductions between 1.10 mSv (12%) and 1.56 mSv (24%) (p < 0.01) were found in the anterior segment and no differences posteriorly and laterally. Total dose reductions between 0.64 (8%) and 0.91 mSv (13%) were found across kVp levels (p < 0.00001). Maximum noise increase with OBTCM was 0.8 HU. With the Canon system, anterior dose reductions of 6–10% and total dose reduction of 0.74–0.76 mSv across kVp levels (p < 0.001) were found with a maximum noise increase of 1.1 HU. For the Siemens system, dose increased by 22–51% anteriorly; except at 100 kVp where no dose difference was found. Noise decreased by 1 to 1.5 HU.ConclusionOrgan based tube current modulation is capable of anterior and total dose reduction with minimal loss of image quality in vendors that do not increase posterior dose.Implications for practiceThis research highlights the importance of being familiar with dose reduction technologies.     

基于风险识别的群组管理对冠状动脉CT血管成像检查依从性及图像质量的影响

目的探究基于风险识别的群组管理对冠状动脉CT血管成像(CTA)检查依从性及图像质量的影响。方法选取2019年1—12月收治的冠心病、均至少接受1次64层CT冠状动脉血管检查患者114例为研究对象,按照两组患者一般资料均衡可比的原则分为观察组和对照组,每组57例。采用问卷调查与量表评估形式,比较两组患者检查依从性及图像质量。结果观察组检查依从性明显优于对照组;观察组检查图像质量优良率高于对照组;观察组平均检查耗时低于对照组,碘对比剂外渗率低于对照组;差异均有统计学意义(P<0.05)。结论基于风险识别的群组管理运用于冠状动脉CTA患者检查过程中,可提高患者检查依从性,提升图像质量,值得临床参考借鉴。     

Evaluation of X-ray table mattresses for radiation attenuation and impact on image quality

IntroductionMattresses in the radiology department tend to be an overlooked aspect of imaging equipment. This paper evaluates the radiation attenuation characteristics of mattresses and the effect they have on image quality.MethodsThirteen mattresses (from new to 20 years of age) were evaluated. Incident air kerma (IAK) was measured in two conditions, with and without mattress over a range of exposure factors using a digital dosimeter. Image quality was assessed by calculating the inverse image quality factor (IQF_inv) using a commercially available phantom (CDRAD) for the same exposure factors. The correlation of age and attenuation and image quality was calculated.ResultsMeasured IAK and image quality was affected by the addition of a mattress with older mattresses having greater attenuation; there is a moderate/large correlation (0.38–0.51) between age and IAK. IQF_inv deteriorated with the addition of a mattress but there was no correlation with age (?0.41 to 0.16). Clinically, there is no impact of any mattress in the study as changes to the exposure factors to account for the attenuation are smaller than the increments in mAs available on X-ray equipment.ConclusionThe results indicate that while the presence of a mattress does impact on transmitted radiation and the quality of the image, the clinical impact is insignificant. Attenuation correlates with age but with no clinical significance. There is no correlation between age and image quality.Implications for practiceQuality control tests for attenuation and impact on image quality are not required in clinical practice. The method could be used by manufacturers to test new materials and mattresses and could provide users with specifications of new products.     

Investigating perceptions of ‘dose creep’ amongst student radiographers: A grounded theory study

IntroductionThe dose creep phenomenon is now a widely recognized concept in diagnostic radiography in light of recent technological advancements transnationally. However, this still remains underexplored amongst radiography students preparing to enter the radiography profession. In response, this study explores the perceptions of dose creep amongst undergraduate student radiographers.MethodsThe methodological approach utilized in this research study was grounded theory. The qualitative approach aimed to uncover findings from a higher education institution in Australia. Six students were recruited and took part in semi-structured interviews. This enabled the exploration of previously uncovered data, leading to the construction of original theory within the clinical and academic environment. The data analysis employed was constant comparative analysis (CCA).ResultsA number of insights emerged from the qualitative data set. For instance, the radiography students understanding of the term ‘dose creep’ and decision making leading to dose creep in the clinical environment is captured. This is further supported with assessment of image evaluation determining appropriate exposure factor selection and future impact upon graduation as diagnostic radiographers. The findings identify some important learning needs and actions for both clinical and academic settings which may help foster good use of X-ray exposures.ConclusionThis paper concludes by affirming some challenges surrounding optimal exposure selection and the known phenomenon, dose creep. Further, this study identifies the importance of learning and teaching in the clinical environment whereby learned behaviour leads to suboptimum practices.Implications for practiceThis study advances the existing evidence base by providing a unique lens into the knowledge and understanding of dose creep amongst radiography students in both academic and clinical contexts. It is anticipated this paper will help practitioners and educators better understand potential instances of dose creep within the clinical environment.     

Abdominal radiograph preliminary clinical evaluation image test bank project

IntroductionLiterature documenting preliminary clinical evaluation (PCE) commonly focuses on the evaluation of musculoskeletal radiographs. Despite this, the professional body suggest that a diagnostic radiographer should be able to provide a PCE for any radiograph.MethodsAn image bank of 30 abdominal radiographs was designed comprising of 17 abnormal cases with a range of pathologies which one could expect to encounter in the emergency department (ED). Participants' were asked to select one of four taxonomies to represent their PCE for each radiograph. Participants' answers were compared to a gold standard PCE taxonomy based on the radiological report. Inferential statistics were applied to assess for any significant different in accuracy between NHS pay bands of the participants.ResultsOn average participants selected an abdominal radiograph PCE taxonomy with a sensitivity of 75.2% and a specificity of 75.7%. Whilst band 7 radiographers selected the most accurate abdominal radiograph PCE and had the highest area under curve (AUC), no significant difference was found in the PCE categorisation of abdominal radiographs by radiographers of all pay bands.ConclusionParticipants' have shown good sensitivity in recognising prominent findings on abdominal radiographs. This sensitivity is however reduced when assessing less obvious radiographic appearances, illustrating areas where additional training would be beneficial. The study provides evidence towards the consideration of an expansion of current practice regarding the implementation of a scheme of abdominal radiograph PCE. Further research with a larger cohort of participants' and a lower abnormal case prevalence would be beneficial to the limited research base.     

Nuclear medicine image interpretation by radiographers: Findings of an accredited postgraduate module

Introduction

The study aimed to analyse the results of radiographer's image interpretation of nuclear medicine (NM) examinations following a nine-month postgraduate module.