Marie-Louise Butler

Are exposure index values consistent in clinical practice? A multi-manufacturer investigation

The advent of digital radiography poses the risk of unnoticed increases in patient dose. Manufacturers have responded to this by offering an exposure index (EI) value to the clinician. Whilst the EI value is a measure of the air kerma at the detector surface, it has been recommended by international agencies as a method of monitoring radiation dose to the patient. Recent studies by the group have shown that EI values are being used in clinical practice to monitor radiation dose and assess image quality. This study aims to compare the clinical consistency of the EI value in computed radiography (CR) and direct digital radiography (DR) systems. An anthropormorphic phantom was used to simulate four common radiographic examinations: skull, pelvis, chest and hand. These examinations were chosen as they provide contrasting exposure parameters, image detail and radiation dose measurements. Four manufacturers were used for comparison: Agfa Gaevert CR, Carestream CR, Philips Digital Diagnost DR and Siemens DR. For each examination, the phantom was placed in the optimal position and exposure parameters were chosen in accordance with European guidelines and clinical practice. Multiple exposures were taken and the EI recorded. All exposure parameters and clinical conditions remained constant throughout. For both DR systems, the EI values remained consistent throughout. No significant change was noted in any examination. In both CR systems, there were noteworthy fluctuations in the EI values for all examinations. The largest for the Agfa system was a variation of 1.88-2.21 for the skull examination. This represents to the clinician a doubling of detector dose, despite all exposure parameters remaining constant. In the Kodak system, the largest fluctuation was seen for the chest examination where the EI ranged from 2560 to 2660, representing approximately an increase of 30 % in radiation dose, despite consistent parameters. The fluctuations seen with the CR systems are most likely due to image processing delay, replacing of the imaging plate and calibration factors. Fluctuations in EI values may result in confusion to the clinician and unnecessary repeat examinations. The reliability of EI values as a feedback mechanism for CR is also questionable.

A Pilot Study to Evaluate the Introduction of an Interprofessional Problem-based Learning Module

Patient care is complex and demands that health professionals work together effectively. Interprofessional education (IPE) encourages collaboration by educating students from different professions together. This study examined the effectiveness of IPE in terms of changing students’ perceptions of teamwork, professional identity, role, competency and autonomy, and the need for interdisciplinary co-operation. Two multidisciplinary cohorts of health science students (n=51 and n=48) elected to participate in a problem-based learning module (PBL). The module included problems addressing areas of professional identity and cases requiring a multidisciplinary team approach. Evaluation was undertaken using the Readiness for Interprofessional Learning Scale (RIPLS) and the Interdisciplinary Education Perception Scale (IPES). Regarding the RIPLS, both cohorts reported significant (p<0.05) improvements in their perceptions of teamwork, collaboration, and positive professional identity. Regarding the IEPS students’ perceptions of professional competency and autonomy improved significantly (p<0.05) in both cohorts. An IPE module delivered using PBL appears valuable for professional development.

Neuroimaging referral for dementia diagnosis: The specialist's perspective in Ireland

Neuroimaging is an increasingly important tool in the diagnostic workup of dementia. Neurologists, geriatricians, and old‐age psychiatrists are involved in key tasks in the diagnostic process, frequently referring patients with suspected dementia for neuroimaging.

The impact of processing delay on the exposure index value

Digital radiography poses the risk of unnoticed increases in patient dose. Manufacturers responded to this by offering an exposure index (EI) value to clinicians. Use of the EI value in clinical practice is encouraged by the American College of Radiology and American Association of Physicists in Medicine. This study assesses the impact of processing delay on the EI value. An anthropormorphic phantom was used to simulate three radiographic examinations; skull, pelvis and chest. For each examination, the phantom was placed in the optimal position and exposures were chosen in accordance with international guidelines. A Carestream (previously Kodak) computed radiography system was used. The imaging plate was exposed, and processing was delayed in various increments from 30 seconds to 24 hours, representing common delays in clinical practice. The EI value was recorded for each exposure. The EI value decreased considerably with increasing processing delay. The EI value decreased by 100 within 25 minutes delay for the chest, and 20 minutes for the skull and pelvis. Within 1 hour, the EI value had fallen by 180, 160 and 100 for the chest, skull and pelvis respectively. After 24 hours, the value had decreased by 370, 350 and 340 for the chest, skull and pelvis respectively, representing to the clinician more then a halving of exposure to the detector in Carestream systems. The assessment of images using EI values should be approached with caution in clinical practice when delays in processing occur. The use of EI values as a feedback mechanism is questioned.

Optimization of Exposure Index values for the antero--posterior pelvis and antero-posterior knee examination

Introduction The American Association of Medical Physicists is currently standardizing the exposure index (EI) value. Recent studies have questioned whether the EI value offered by manufacturers is optimal. This current work establishes optimum EIs for the antero-posterior (AP) projections of a pelvis and knee on a Carestream Health (Kodak) CR system and compares these with manufacturers recommended EI values from a patient dose and image quality perspective. Methodology Human cadavers were used to produce images of clinically relevant standards. Several exposures were taken to achieve various EI values and corresponding entrance surface doses (ESD) were measured using thermoluminescent dosimeters. Image quality was assessed by 5 experienced clinicians using anatomical criteria judged against a reference image. Visualization of image specific common abnormalities was also analyzed to establish diagnostic efficacy. Results A rise in ESD for both examinations, consistent with increasing EI was shown. Anatomic image quality was deemed to be acceptable at an EI of 1560 for the AP pelvis and 1590 for the AP knee. From manufacturers recommended values, a significant reduction in ESD (p=0.02) of 38% and 33% for the pelvis and knee respectively was noted. Initial pathological analysis suggests that diagnostic efficacy at lower EI values may be projection-specific. Conclusion The data in this study emphasize the need for clinical centres to consider establishing their own EI guidelines, and not necessarily relying on manufacturers recommendations. Normal and abnormal images must be used in this process.

Do radiographers base the diagnostic acceptability of a radiograph on anatomical structures

Background The document “European Guidelines on Quality Criteria for Diagnostic Radiographic Images” describes the visualisation of anatomical criteria to which a radiograph of diagnostic quality should comply. This research investigates the correlation between the evaluation of anatomical structures, presented in the European guidelines, and the classification of radiographs for diagnostic acceptability. Methods Sixteen radiographers classified 22 chest radiographs in terms of diagnostic acceptability using the RadLex categories, and scored the representation of five anatomical criteria on a scale from 1 to 5. All radiographs were visualised with ViewDex on a DICOM calibrated display. Observers were recruited in Belgium and Ireland. An interclass correlation coefficient was applied to evaluate internal consistency for each observer group. A Mann–Whitney U-test was applied to investigate differences in classification between countries. The relationship with the evaluation of anatomical structures was investigated with ordinal logistic regression. Results Both groups of observers performed with acceptable consistency. The Mann–Whitney U test illustrated a significant difference in classification between the two countries. The ordinal logistic regression indicated for each country a weak correlation between the RadLex and the anatomical structures. Certain factors in the radiograph, possibly others than anatomical elements, must be significantly better before the observer will attribute a higher RadLex score. Conclusion The relationship between the evaluation of anatomical criteria and the diagnostic acceptability is weak for both countries. When assigning a radiograph to a certain category of acceptability, other factors influence the decision.

The introduction of mandatory CPD for newly state registered diagnostic radiographers: An Irish perspective

INTRODUCTION Irish diagnostic radiography has undergone significant change with the dual introduction of state registration and mandatory Continuing Professional Development (CPD) in October 2015. We aimed to investigate motivators and barriers around CPD participation, mechanisms of CPD delivery and confidence of radiographers in using e-learning. METHODS A questionnaire distributed nationally during this period captured Radiographer opinion through the use of closed and open questions. The questionnaire was distributed in hard copy and online formats depending on site preference. RESULTS 71% of centres participated, rendering 453 responses in total from a possible 1222 respondents employed in those sites at the time of the survey. A varied range of ages and post qualification experience were represented. Respondents indicated use of several CPD options with the majority considering CPD to be important, very important or critical. Social media as a mechanism of CPD delivery was considered acceptable by 48%, while online learning elicited responses ranging from not confident to absolutely confident. Top motivators for CPD activity included interest, developing new knowledge and competency. Principal barriers included funding, time allocation and location issues. CONCLUSION This study identified Radiographer desire to undertake CPD and the need for developing online CPD offerings. An overall positive perception towards CPD was noted however barriers were identified which require specific redress strategies.

What do people with dementia and their carers want to know about neuroimaging for dementia

Neuroimaging forms an important part of dementia diagnosis. Provision of information on neuroimaging to people with dementia and their carers may aid understanding of the pathological, physiological and psychosocial changes of the disease, and increase understanding of symptoms. This qualitative study aimed to investigate participants’ knowledge of the dementia diagnosis pathway, their understanding of neuroimaging and its use in diagnosis, and to determine content requirements for a website providing neuroimaging information. Structured interviews and a focus group were conducted with carers and people with dementia. The findings demonstrate an unmet need for information on neuroimaging both before and after the examination. Carers were keen to know about neuroimaging at a practical and technical level to help avoid diagnosis denial. People with dementia requested greater information, but with a caveat to avoid overwhelming detail, and were less likely to favour an Internet resource.

Variability amongst radiographers in the categorization of clinical acceptability for digital trauma radiography

Introduction: Radiographers evaluate anatomical structures to judge clinical acceptability of a radiograph. Whether a radiograph is deemed acceptable for diagnosis or not depends on the individual decision of the radiographer. Individual decisions cause variation in the accepted image quality. To minimise these variations definitions of acceptability, such as in RadLex, were developed. On which criteria radiographers attribute a RadLex categories to radiographs is unknown. Insight into these criteria helps to further optimise definitions and reduce variability in acceptance between radiographers. Therefore, this work aims the evaluation of the correlation between the RadLex classification and the evaluation of anatomical structures, using a Visual Grading Analysis (VGA) Methods: Four radiographers evaluated the visibility of five anatomical structures of 25 lateral cervical spine radiographs on a secondary class display with a VGA. They judged clinical acceptability of each radiograph using RadLex. Relations between VGAS and RadLex category were analysed with Kendall’s Tau correlation and Nagelkerke pseudo-R². Results: The overall VGA score (VGAS) and the RadLex score correlate (rτ= 0.62, p<0.01, R2=0.72) strongly. The observers’ evaluation of contrast between bone, air (trachea) and soft tissue has low value in predicting (rτ=0.55, p<0.01, R2=0.03) the RadLex score. The reproduction of spinous processes (rτ=0.67, p<0.01, R2=0.31) and the evaluation of the exposure (rτ=0.65, p<0.01, R2=0.56) have a strong correlation with high predictive value for the RadLex score. Conclusion: RadLex scores and VGAS correlate positively, strongly and significantly. The predictive value of bony structures may support the use of these in the judgement of clinical acceptability. Considerable inter-observer variations in the VGAS within a certain RadLex category, suggest that observers use of observer specific cut-off values.

Current Practice in the Referral of Individuals with Suspected Dementia for Neuroimaging by General Practitioners in Ireland and Wales.

Objectives While early diagnosis of dementia is important, the question arises whether general practitioners (GPs) should engage in direct referrals. The current study investigated current referral practices for neuroimaging in dementia, access to imaging modalities and investigated related GP training in Ireland and North Wales. Methods A questionnaire was distributed to GPs in the programme regions which included approximately two thirds of all GPs in the Republic of Ireland and all general practitioners in North Wales. A total of 2,093 questionnaires were issued. Results 48.6% of Irish respondents and 24.3% of Welsh respondents directly referred patients with suspected dementia for neuroimaging. Irish GPs reported greater direct access to neuroimaging than their Welsh counterparts. A very small percentage of Irish and Welsh GPs (4.7% and 10% respectively) had received training in neuroimaging and the majority who referred patients for neuroimaging were not aware of any dementia-specific protocols for referrals (93.1% and 95% respectively). Conclusions The benefits of direct GP access to neuroimaging investigations for dementia have yet to be established. Our findings suggest that current GP speciality training in Ireland and Wales is deficient in dementia-specific and neuroimaging training with the concern being that inadequate training will lead to inadequate referrals. Further training would complement guidelines and provide a greater understanding of the role and appropriateness of neuroimaging techniques in the diagnosis of dementia.