Image interpretation performance: A longitudinal study from novice to professional

PurposeUniversities need to deliver educational programmes that create radiography graduates who are ready and able to participate in abnormality detection schemes, ultimately delivering safe and reliable performance because junior doctors are exposed to the risk of misdiagnosis if unsupported by other healthcare professionals. Radiographers are ideally suited to this role having the responsibility for conducting the actual X-ray examination.MethodThe image interpretation performance of one cohort of student radiographers was measured upon enrolment from UCAS in the first week of university education and then again prior to graduation using RadBench (n = 23).ResultsThe results identified that novices have a range of natural image interpretation skills; accuracy 35–85%, sensitivity 45–100%, specificity 15–85%, mean ROC 0.691. Graduates presented a narrower range; accuracy 60–90%, sensitivity 40–100%, specificity 60–90%, mean ROC 0.841. The positive shift in graduate mean accuracy (+16%) was driven by increases in specificity (+27%) rather than sensitivity (+5%). No statistically significant differences (ANOVA) could be found between age group, gender and previous education however trends were identified. 56.5% of the population (n = 13) met a benchmark accurate standard of 80%, including one graduate who met 90%.ConclusionImage interpretation testing at the point of UCAS entry is a useful indicator of future performance and is a recommended factor for consideration as part of the selection process. Whilst image interpretation now forms an integral part of undergraduate radiography programmes, new graduates may not necessary possess the reliability in decision making to justify participation in abnormality detection schemes, highlighting the need for continuous professional development.     

Development of a valid and reliable test to assess trauma radiograph interpretation performance

ObjectivesThe purpose of this investigation was to develop and examine the preliminary validity and reliability among radiographers of a test to assess trauma radiograph interpretation performance suitable for use among health professionals.MethodsStage 1 examined 14,159 consecutive appendicular and axial examinations from a hospital emergency department over a 12 month period to quantify a typical anatomical region case-mix of trauma radiographs. A sample of radiographic cases representative of affected anatomical regions was then developed into the Image Interpretation Test (IIT). Stage 2 involved prospective investigations of the IIT's reliability (inter-rater, intra-rater, internal consistency) and validity (concurrent) among 41 radiographers.ResultsThe IIT included 60 cases. The median (interquartile range) clinical experience of participants was 5 (2–10) years. Case scores were internally consistent (Cronbach's alpha = 0.90). Favourable inter-rater reliability (kappa > 0.70 for 58/60 cases, Intra-class correlation coefficient (ICC) > 0.99 for total score) and intra-rater reliability (kappa > 0.90 for 60/60 cases, ICC > 0.99 for total score) was observed. There was a positive association between radiographers' confidence in image interpretation and IIT score (coefficient = 1.52, r-squared = 0.60, p < 0.001).ConclusionsThe IIT developed during this investigation included a selection of radiographic cases consistent with anatomical regions represented in an adult trauma case-mix. This study has also provided foundational preliminary evidence to support the reliability and validity of the IIT among radiographers. The findings suggest that it is possible to assess image interpretation performance of adult trauma radiographs with this test.     

Variation in assessments of suitability and number of contributors for DNA mixtures

The interpretation of a DNA mixture (a sample that contains DNA from two or more people) depends on a laboratory/analyst’s assessment of the suitability of the sample for comparison/analysis, and an assessment of the number of contributors (NoC) present in the sample. In this study, 134 participants from 67 forensic laboratories provided a total of 2272 assessments of 29 DNA mixtures (provided as electropherograms). The laboratories’ responses were evaluated in terms of the variability of suitability assessments, and the accuracy and variability of NoC assessments. Policies and procedures related to suitability and NoC varied notably among labs. We observed notable variation in whether labs would assess a given mixture as suitable or not, predominantly due to differences in lab policies: if two labs following their standard operating procedures (SOPs) were given the same mixture, they agreed on whether the mixture was suitable for comparison 66% of the time. Differences in suitability assessments have a direct effect on variability in interpretations among labs, since mixtures assessed as not suitable would not result in reported interpretations. For labs following their SOPs, 79% of assessments of NoC were correct. When two different labs provided NoC responses, 63% of the time both labs were correct, and 7% of the time both labs were incorrect. Incorrect NoC assessments have been shown to affect statistical analyses in some cases, but do not necessarily imply inaccurate interpretations or conclusions. Most incorrect NoC estimates were overestimates, which previous research has shown have less of an effect on likelihood ratios than underestimates.     

Empirical support for the reliability of DNA evidence interpretation in Australia and New Zealand

The results of empirical testing of forensic DNA probabilities for Australian and New Zealand populations is reported. It is concluded that if consideration is given to relatedness and subpopulation effects, the current model used in most of Australia and New Zealand appears to give very good predictions.     

Utilising allelic dropout probabilities estimated by logistic regression in casework

Some advanced methods for DNA profile interpretation require a probability for the event of dropout. Methods have been suggested based on logistic regression. Two of these respectively use a proxy for template that is constant across loci and one that is modelled using an exponential curve. Both of these methods allow different modelling constants from each locus. A variant of the model using an exponential curve is discussed. This variant constrains the constants to be the same for every locus. We test these two methods and the variant by developing the constants (training) on one set of data and testing them on another. This mimics the likely use in casework. We find that the new variant appears to be the most useful in that it performs better than the other two options when trained on one data set and used on another. The hypothesised reason for this is that locus to locus variation in amplification efficiency varies with time, multimix batch, or from sample to sample.     

十二指肠间质瘤X线与CT影像诊断对照分析

目的对照分析十二指肠问质瘤x线钡餐造影与CT检查的影像表现,以提高对十二指肠问质瘤的诊断水平。方法回顾11例十二指肠间质瘤患者临床资料、X线造影及cT影像表现,并经病理及免疫组织化学法证实。结果l1例患者中7例位于十二指肠降部（63．6％）,3例位于十二指肠水平部（27．3％）．1例位于十二指肠球部（9．1％）。X线钡餐造影表现1l例患者中十二指肠不同程度狭窄9例;局部充盈缺损或龛影、黏膜变平或破坏、消失11例;2例形成窦道样改变。cT表现,平扫：11例患者中有7例表现为均匀软组织密度,4例表现为不均匀软组织密度,其内可见液化坏死;增强扫描：动脉期、静脉期病灶实性部分强化,静脉期强化明显,液化坏死部分无强化,6例与周同组织分界清晰,5例与周同组织分界不清。结论X线与cT检查都可以发现十二指肠间质瘤,二者互为补充,可提高十二指肠问质瘤判断正确率,为临床进一步诊治提供帮助。     

多发性硬化诊断标准的进展与解读

多发性硬化是一种中枢神经系统脱髓鞘性疾病,临床特点是病灶播散广泛。本文复习了近30年来多发性硬化诊断标准的进展,并作解读。     

文化信息解读是医易经典学习的重要方法

文章指出学习研究医、易经典的重要环节是对经典中文化信息的准确解读。解读要点有三:一是对作为古代文化信息基本载体的语言、文字、符号、图形等具体文化内涵的正确考辨;二是对百科文化信息相互渗透之复杂关系的深刻理解;三是对学术发展过程中文化信息演变的正确把握。     

One voice, different tunes: issues raised by dual analysis of a segment of qualitative data

Qualitative data analysis is a complex and contested part of the research process that has received limited theoretical attention. This paper explores the relationship between the way in which data are analysed and the nature of findings that emerge. It does this in response to demands to recognize the multiple voices that inform representations of reality, and debates about whether the interpretation of data reveals or constructs meaning. A small segment of data provided by one informant is subjected to both thematic and narrative analysis and the different perspectives that emerge are discussed with reference to whether different kinds of analysis lead to different kinds of meaning being imputed to the same text. The paper suggests that, rather than provide a unified and ever-more refined version of 'reality', the use of dual or multiple analysis helps to elucidate alternative interpretations of the data which might escape consideration with the use of a single approach.