A comparison of perceived image quality between computer display monitors and augmented reality smart glasses.

INTRODUCTION: Augmented-reality (AR) smart glasses provide an alternative to standard computer display monitors (CDM). AR smart glasses may provide an opportunity to improve visualisation during fluoroscopy and interventional radiology (IR) procedures when there can be difficulty in viewing intra-procedural images on a CDM. The aim of this study was to evaluate radiographer perception of image quality (IQ) when comparing CDM and AR smart glasses. METHODS: 38 radiographers attending an international congress evaluated ten fluoroscopic-guided surgery and IR images on both a CDM (1920 × 1200 pixels) and a set of Epson Moverio BT-40 AR smart glasses (1920 × 1080 pixels). Participants provided oral responses to pre-defined IQ questions generated by study researchers. Summative IQ scores for each participant/image were compared between CDM and AR smart glasses. RESULTS: Of the 38 participants, the mean age was 39 ± 1 years. 23 (60.5%) participants required corrective glasses. In terms of generalisability, participants were from 12 different countries, the majority (n = 9, 23.7%) from the United Kingdom. For eight out of ten images, the AR smart glasses demonstrated a statistically significant increase in perceived IQ (median [IQR] 2.0 [-1.0 to 7.0] points) when compared to the CDM. CONCLUSION: AR smart glasses appear to show improvements in perceived IQ when compared to a CDM. AR smart glasses could provide an option for improving the experiences of radiographers involved in image-guided procedures and should be subject to further clinical evaluations. IMPLICATIONS FOR PRACTICE: Opportunities exist to improve perceived IQ for radiographers when reviewing fluoroscopy and IR images. AR smart glasses should be further evaluated as a potential opportunity to improve practice when visual attention is split between positioning equipment and image review.

Post COVID-19 trends in simulation use within diagnostic radiography and radiation therapy education.

PURPOSE: Simulation is used within medical radiation science training. Recent global events and simulation resource uptake has led to significant changes. The aim of this study was to capture post COVID-19 trends and activity of simulation-based education (SBE) in diagnostic radiography and radiation therapy. METHODS: An online survey was designed to investigate the role of simulation within diagnostic radiography and radiation therapy education. Survey design was based on literature and experience within the research team. Questions were based around access and use of simulation, future trends and the effects of COVID-19. Participants were diagnostic radiography and/or radiation therapy educators. Data captured in this study was undertaken in March 2022 and compared with previous data from Bridge and colleagues (2021). RESULTS: Sixty-seven responses were received across five continents (two from North/South America), Europe was the most widely represented (n = 58, 87%). Fifty-three (79%) of participants reported that they use simulation as part of their teaching and learning. Twenty-seven (51%) respondents reported that they had increased their use of simulation because of COVID-19. Sixteen (30%) respondents stated that they were now able to enrol more students because of the pandemic. Fixed models and immersive environments were the two most common simulation activities. Participants reported, to different degrees, that simulation was used across all parts of the curriculum. CONCLUSIONS: Simulation is deeply embedded into diagnostic radiography and radiation therapy education. Evidence suggests that the growth of simulation may be slowing. Opportunities exist for the development of guidance, training and best practice resources around simulation. IMPLICATIONS FOR PRACTICE: Simulation is a key pedagogical approach for diagnostic radiography and radiation therapy education. Key stakeholders now need to work collaboratively to define standards and best practices.

Erect pelvic radiography with fat tissue displacement: Impact on radiation dose and image quality.

INTRODUCTION: Pelvic radiography is one of the most frequent general radiography imaging procedures. Pelvic radiography is usually performed in the supine position, but in some cases erect imaging is performed. The aim of this study was to determine whether radiation dose and image quality differ between two different erect pelvic radiographic procedures in overweight and obese patients, with and without displacement of anterior adipose tissue. METHODS: This research was a two-part study. The first part of the study was to determine a suitable fat displacement band that would not produce artifacts on the resulting radiograph when fat tissue was displaced. The second part of the study was performed in a clinical setting on 60 overweight or obese patients (BMI ≥25) referred for erect pelvic imaging. Patients were randomly divided into two equal groups, half of which displaced adipose tissue from the region of interest and the other group did not. Waist and hip circumference, height, weight, dose-area- product (DAP), primary field size, source-to-skin distance, mAs, and kV were measured. Body Mass Index (BMI), entrance surface dose (ESD), and effective dose (ED) were then calculated. The resulting images were evaluated by three radiologists. RESULTS: It was found that a thin cotton triangular bandage produced no visible radiographic artefacts. In the group of patients using the fat displacement protocol, a statistically significant reduction in waist circumference (4.7%), DAP (38.5%), ESD (44%) and ED (38.7%) were observed (p < 0.05). In addition, a significant (p < 0.05) increase was found for all the observed image quality criteria and overall total image score with exception of sacroiliac joint, iliac crest and pubic/ischial rami. CONCLUSION: Based on the results, the use of the adipose tissue displacement protocol for radiography of the pelvis and hip in the erect position in overweight and obese patients is recommended. IMPLICATIONS FOR PRACTICE: The use of cotton bands to remove adipose tissue during pelvic imaging in obese and overweight patients results in a reduction of radiation dose received by the patient and improves image quality. This technique is quick, easy, and inexpensive.

The gendered impact of the COVID-19 pandemic on academics working in medical imaging and radiation therapy.

INTRODUCTION: Healthcare workers have been particularly impacted by the COVID-19 pandemic, as have those educating them, albeit differently. Several papers have identified a gendered difference in the impact of the pandemic. This study aims to determine impact of COVID-19 on the health and wellbeing of Medical Imaging and Radiation Therapy (MIRT) academics. METHODS: An electronic survey was designed in English on Qualtrics and distributed via email and online platforms to MIRT academics. Fifty-one questions were used; demographic (n = 9), work patterns (n = 11), general health (n = 8), mental health (n = 2), physical health (n = 10), and workload (n = 11). Overall, 46 were quantitative and five were qualitative 'open-ended' questions. The survey was open between 3rd March 2021 to 1st May 2021. Quantitative analysis was carried out using MS Excel v 16.61.1ss and SPSS v26. RESULTS: The survey reached 32 countries globally and 412 participants; 23.5% identified as men (n = 97) and 76.5% as women (n = 315). Women reported worse sleep quality than men and overwhelmingly felt they would not like to work remotely again if given a choice. A higher percentage of males, 73% versus 40.5% of females reported getting outdoors less. The CORE-10 validated questionnaire found that 10.3% of males (n = 42) and 2.7% of females (n = 11) experienced severe psychological distress the week immediately before the survey was conducted. CONCLUSION: While the study has identified some gender-related differences in the impact of COVID-19 on the mental and physical health of MIRT academics, both males and females have experienced significant deterioration in health and wellbeing due to the pandemic. IMPLICATION FOR PRACTICE: Developing mental health support for MIRT academics and defining optimum methods for raising awareness is recommended.

Artificial Intelligence: Guidance for clinical imaging and therapeutic radiography professionals, a summary by the Society of Radiographers AI working group.

INTRODUCTION: Artificial intelligence (AI) has started to be increasingly adopted in medical imaging and radiotherapy clinical practice, however research, education and partnerships have not really caught up yet to facilitate a safe and effective transition. The aim of the document is to provide baseline guidance for radiographers working in the field of AI in education, research, clinical practice and stakeholder partnerships. The guideline is intended for use by the multi-professional clinical imaging and radiotherapy teams, including all staff, volunteers, students and learners. METHODS: The format mirrored similar publications from other SCoR working groups in the past. The recommendations have been subject to a rapid period of peer, professional and patient assessment and review. Feedback was sought from a range of SoR members and advisory groups, as well as from the SoR director of professional policy, as well as from external experts. Amendments were then made in line with feedback received and a final consensus was reached. RESULTS: AI is an innovative tool radiographers will need to engage with to ensure a safe and efficient clinical service in imaging and radiotherapy. Educational provisions will need to be proportionately adjusted by Higher Education Institutions (HEIs) to offer the necessary knowledge, skills and competences for diagnostic and therapeutic radiographers, to enable them to navigate a future where AI will be central to patient diagnosis and treatment pathways. Radiography-led research in AI should address key clinical challenges and enable radiographers co-design, implement and validate AI solutions. Partnerships are key in ensuring the contribution of radiographers is integrated into healthcare AI ecosystems for the benefit of the patients and service users. CONCLUSION: Radiography is starting to work towards a future with AI-enabled healthcare. This guidance offers some recommendations for different areas of radiography practice. There is a need to update our educational curricula, rethink our research priorities, forge new strong clinical-academic-industry partnerships to optimise clinical practice. Specific recommendations in relation to clinical practice, education, research and the forging of partnerships with key stakeholders are discussed, with potential impact on policy and practice in all these domains. These recommendations aim to serve as baseline guidance for UK radiographers. IMPLICATIONS FOR PRACTICE: This review offers the most up-to-date recommendations for clinical practitioners, researchers, academics and service users of clinical imaging and therapeutic radiography services. Radiography practice, education and research must gradually adjust to AI-enabled healthcare systems to ensure gains of AI technologies are maximised and challenges and risks are minimised. This guidance will need to be updated regularly given the fast-changing pace of AI development and innovation.

International perspectives on radiography practice education.

INTRODUCTION: The radiography profession is built upon strong educational foundations which help ensure graduate radiographers have the required knowledge, skills, and competence to practise safely and effectively. Changing clinical practices, service needs, technological developments, regulatory changes, together with our growing professional evidence-base, all contribute to the need for our curricula to responsive and continually reviewed and enhanced. This study aims to explore similarities and differences in training curricula and follows a 2012 global survey on radiography education and more recent surveys undertaken by the European Federation of Radiographer Societies (EFRS). METHODS: An online questionnaire, based on previous EFRS education and clinical education surveys, which comprised of open and closed questions and consisted of sections designed to ascertain data on: type, level and duration of education programmes leading to an initial or pre-registration qualification in radiography/medical radiation practice, pre-clinical skill development and clinical placement within programmes. The survey was distributed via social media channels and through an international network of professional societies. Descriptive statistics are reported for most analyses while open questions were analysed thematically. RESULTS: Responses were received from 79 individuals from 28 identified countries across four continents. This represented a total of 121 different pre-registration/entry level programmes offered across these institutions. While dedicated diagnostic radiography programmes were most common (42/121), almost one-third of programmes (40/121) offered two or more areas of specialisation within the curriculum. The average of total hours for clinical placement were 1397 h for diagnostic radiography programmes; 1300 h for radiation therapy programmes; 1025 h for nuclear medicine programmes; and 1134 h for combined specialisation programmes, respectively. Institutions provided a range of physical and virtual systems to support pre-clinical skills development. CONCLUSION: Around the world, radiography programmes vary considerably in terms of their level, duration, programme type, pre-clinical and clinical training, use of simulation, and also in terms of class sizes, student/staff ratios, and graduate employment prospects. The ability of graduates to work independently in areas covered within their programmes varied considerably. While some changes around simulation use were evident, given the impact of COVID-19 it would be beneficial for future research to investigate if pre-clinical and clinical education hours or use of simulation resources has changed due to the pandemic. IMPLICATIONS FOR PRACTICE: The heterogeneity that exists between radiography programmes presents a significant challenge in terms of the mutual recognition of qualifications and the international movement of the radiographer workforce.

Renal doppler indices and their correlation with laboratory indices of human immunodeficiency virus sero-positive adult individuals.

INTRODUCTION: Renal Doppler resistive index (RI) and pulsatility index (PI) values are potentially more sensitive at detecting renal abnormalities when compared to standard laboratory indices in patients with HIV/AIDS. To the best of our knowledge, there are no published research articles on renal Doppler indices and their correlation with laboratory indices of HIV sero-positive adult individuals. This study aimed to assess the renal function of HIV-sero-positive adults using RI and PI, and correlating these indices against laboratory values. METHODS: A prospective cross-sectional study was conducted from July 2019 to April 2020. A purposive sampling method was employed and included 396 HIV sero-positive adult individuals. Sampling for the renal RI and PI was performed at the level of the inter-lober arteries, in between the medullary pyramids. An RI value above 0.70 and a PI value above 1.56 were consider abnormal. Serum creatine and urea together with evidence of proteinuria were recorded at the time of scanning. RESULTS: Forty-three (10.9%) men had an abnormal RI, 32 (8.1%) had abnormal PI, five (2.5%) had abnormal creatinine, two (1%) abnormal urea and eight (4.1%) with proteinuria. In women, 29 (7.3%) had abnormal RI, 22 (5.6%) abnormal PI, four (2%) abnormal creatinine and urea and six (3%) had proteinuria. There was a statistically significant weak positive correlation between RI and PI and serum creatinine and urea (r > 0.2, P < 0.05). CONCLUSION: The proportion of patients with abnormal RI and PI was higher than the proportion of participants with abnormal serum urea, creatinine and proteinuria. Renal Doppler indices could be used be used in the early assessment of renal function in HIV sero-positive adults individuals. IMPLICATIONS FOR PRACTICE: Serum creatinine and urea are routinely used to evaluate renal function in patients with HIV/AIDS. Findings from this initial study show that RI and PI could be used detecting early renal abnormalities when compared to standard laboratory values.

An investigation into the variability of radiographers assessing body composition prior to CT contrast media administration.

INTRODUCTION: To evaluate and report the variability of radiographers in determining a patient's body type and using this to determine contrast media (CM) volumes for chest computed tomography (CT). METHODS: This prospective study recruited 50 patients undergoing chest CT examinations. Three radiographers independently used two methods to determine patient body type and consequently CM volume. In Method 1, subjective evaluation of body type together with patient weight determined CM volume. In Method 2, patient weight along with additional criteria applied by the radiographer determined CM volume. Both the determination of body type and CM volumes were compared in terms of agreement and variability between radiographers, and between methods. RESULTS: Fleiss' kappa was lower (0.583) for Method 1 when compared to Method 2 (0.926) indicating stronger agreement in the radiographer determination of body type for Method 2. Median (IQR) CM volume was 95.0 mL (85.0-110.0) for Method 1, compared to 92.5 mL (85.0-100.0) for method 2 (P < 0.001). CONCLUSION: Method 2 provided greater agreement in determination of body type, and reduction of CM volumes compared to Method 1. IMPLICATIONS FOR PRACTICE: Determining body type as part of a CT CM strategy can be subjective and enhanced methods are required to ensure that the most appropriate CM volumes are reliably used.

The validity and reliability of the exposure index as a metric for estimating the radiation dose to the patient.

INTRODUCTION: With the introduction of digital radiography, the feedback between image quality and over-exposure has been partly lost which in some cases has led to a steady increase in dose. Over the years the introduction of exposure index (EI) has been used to resolve this phenomenon referred to as 'dose creep'. Even though EI is often vendor specific it is always a related of the radiation exposure to the detector. Due to the nature of this relationship EI can also be used as a patient dose indicator, however this is not widely investigated in literature. METHODS: A total of 420 dose-area-product (DAP) and EI measurements were taken whilst varying kVp, mAs and body habitus on two different anthropomorphic phantoms (pelvis and chest). Using linear regression, the correlation between EI and DAP were examined. Additionally, two separate region of interest (ROI) placements/per phantom where examined in order to research any effect on EI. RESULTS: When dividing the data into subsets, a strong correlation between EI and DAP was shown with all R-squared values > 0.987. Comparison between the ROI placements showed a significant difference between EIs for both placements. CONCLUSION: This research shows a clear relationship between EI and radiation dose which is dependent on a wide variety of factors such as ROI placement, body habitus. In addition, pathology and manufacturer specific EI's are likely to be of influence as well. IMPLICATIONS FOR PRACTICE: The combination of DAP and EI might be used as a patient dose indicator. However, the influencing factors as mentioned in the conclusion should be considered and examined before implementation.

Optimising image quality and radiation dose for neonatal incubator imaging.

INTRODUCTION: Neonates often require imaging within incubators however limited evidence exists as to the optimal method and acquisition parameters to achieve these examinations. This study aims to standardise and optimise neonatal chest radiography within incubators. METHODS: A neonatal anthropomorphic phantom was imaged on two different incubators under controlled conditions using a DR system. Exposure factors, SID and placement of image receptor (direct v tray) were explored whilst keeping all other parameters consistent. Image quality was evaluated using absolute visual grading analysis (VGA) with contrast-to-noise ratio (CNR) also calculated for comparison. Effective dose was established using Monte Carlo simulation using entrance surface dose within its calculations. RESULTS: VGA and CNR reduced significantly (p < 0.05) whilst effective dose increased significantly (p < 0.05) for images acquired using the incubator tray. The optimal combinations of parameters for incubator imaging were: image receptor directly behind neonate, 0.5 mAs, 60 kV at 100 cm SID, however, if tray needs to be used then these need to be adapted to: 1 mAs at maximum achievable SID. Effective dose was highest for images acquired using both incubator tray and 100 cm SID owing to a decrease in focus to skin distance. There is significant increase (p < 0.01) in VGA between using 0.5 mAs and 1 mAs but an apparent lack of increase between 1 and 1.5 mAs. CONCLUSION: Using the incubator tray has an adverse effect on both image quality and radiation dose for incubator imaging. Direct exposure is optimal for this type of examination but if tray needs to be used, both mAs and SID need to be increased slightly to compensate. IMPLICATIONS FOR PRACTICE: This study can help inform practice in order to both standardise and optimise chest imaging for neonates in incubators.

Neonatal chest radiography: Influence of standard clinical protocols and radiographic equipment on pathology visibility and radiation dose using a neonatal chest phantom.

INTRODUCTION: Little is known about the variations in pathology visibility (PV) and their corresponding radiation dose values for neonatal chest radiography, between and within hospitals. Large variations in PV could influence the diagnostic outcome and the variations in radiation dose could affect the risk to patients. The aim of this study is to compare the PV and radiation dose for standard neonatal chest radiography protocols among a series of public hospitals. METHODS: A Gammex 610 neonatal chest phantom was used to simulate the chest region of neonates. Radiographic acquisitions were conducted on 17 X-ray machines located in eight hospitals, utilising their current neonatal chest radiography protocols. Six qualified radiographers assessed PV visually using a relative visual grading analysis (VGA). Signal to noise ratios (SNR) and contrast to noise ratios (CNR) were measured as a measure of image quality (IQ). Incident air kerma (IAK) was measured using a solid-state dosimeter. RESULTS: PV and radiation dose varied substantially between and within hospitals. For PV, the mean (range) VGA scores, between and within the hospitals, were 2.69 (2.00-3.50) and 2.73 (2.33-3.33), respectively. For IAK, the mean (range), between and within the hospitals, were 24.45 (8.11-49.94) µGy and 34.86 (22.26-49.94) µGy, respectively. CONCLUSION: Between and within participating hospitals there was wide variation in the visibility of simulated pathology and radiation dose (IAK). IMPLICATIONS FOR PRACTICE: X-ray units with lower PV and higher doses require optimisation of their standard clinical protocols. Institutions which can offer acceptable levels of PV but with lower radiation doses should help facilitate national optimisation processes.

Can the anode heel effect be used to optimise radiation dose and image quality for AP pelvis radiography?

INTRODUCTION: A study was conducted to determine whether the anode heel effect can be used to influence optimisation of radiation dose and image quality (IQ) for AP pelvis radiography. METHODS: ATOM dosimetry phantom and an anthropomorphic phantom were positioned for AP pelvis. Using a CR system, images were acquired and doses were measured with phantom feet toward anode and then feet toward cathode. Exposure factors (kVp, mAs and SID) were systematically generated using a factorial design. Images were scored visually for quality using relative visual grading together with a 3 point Likert scale. Signal to noise ratio was also calculated as a physical measure of image quality. Dosimetry data were collected for the ovaries and testes. RESULTS: The optimum technique for male, which resulted in lower dose and suitable image quality, was with feet positioned toward the anode (0.80 ± 0.03 mGy; SNR of 38 ± 2.9; visual IQ score 3.13 ± 0.35). The optimum technique for female was with feet toward anode (0.23 ± 0.02 mGy; SNR of 34.7 ± 2.6; visual IQ score 3.15 ± 0.26). kVp had the biggest effect on both visual and physical image quality metrics (p < 0.001) for both tube orientations, whereas SID had the lowest effect on both visual and physical image quality metrics compared with mAs and kVp (p < 0.001). The effect of SID on the SNR was not significant (p > 0.05) with feet toward anode. CONCLUSION: Positioning the patient with feet toward the anode, as opposed to the cathode, has no adverse effect on visual image quality assessment but it does have an effect on physical image quality. IMPLICATIONS FOR PRACTICE: This study would add a new clinical concept in positioning of AP pelvis radiography especially for male positioning.

Initial single centre experiences of a radiographer advanced practitioner led nephrostomy exchange programme.

INTRODUCTION: To evaluate the technical success, radiation dose, complications and costs from the introduction of a radiographer-led nephrostomy exchange service. METHODS: Post-graduate qualified interventional radiographers with several years' experience in performing other interventional procedures began performing nephrostomy exchanges. Training was provided by an interventional radiologist. Each radiographer performed ten procedures under direct supervision followed by independent practice with remote supervision. Each radiographer was then responsible for the radiological report, discharge, re-referral for further exchange and, where indicated, sending urine samples for culture and sensitivity. Data extraction included the time interval between exchanges, radiation dose/screening time and complications. RESULTS: Thirty-eight long-term nephrostomy patients had their histories interrogated back to the time of the initial insertion. The mean (range) age at nephrostomy insertion was 67 (35-93) years and 65% were male. Indications for nephrostomy were prostatic or gynaecological malignancy, ureteric injury, bulky lymphoma and post-transplant ureteric stricture. A total of 170 nephrostomy exchanges were performed with no statistically significant differences in the radiation dose, fluoroscopy time nor complication rates between consultants and radiographers. There was, however, a statistically significant reduction in the time interval between nephrostomy exchanges for the radiographer group (P = 0.022). CONCLUSION: Interventional radiographers can provide a safe, technically successful nephrostomy exchange program with radiation doses equivalent to radiologists. This is a cost-effective solution to the capacity issues faced in many departments, whilst providing career progression, job satisfaction and possibly improved care. IMPLICATIONS FOR PRACTICE: Radiographer-led interventional services should be considered by other institutions as a means of providing effective nephrostomy exchanges.

A comparative study of pain experienced during successive mammography examinations in patients with a family history of breast cancer and those who have had breast cancer surgery.

INTRODUCTION: To measure mammography-related pain in two groups of women undergoing regular surveillance as a baseline for future care. METHODS: Following ethical approval, two hundred and forty two women aged 32-84 years (mean 54), were invited by written invitation to participate in the study. Two hundred women accepted the invitation, 100 women had a family history (FH) of breast cancer, 100 had undergone conservative surgery (FU) for breast cancer and were currently asymptomatic. A validated pain scale was used to score the participants' perceived pain before compression based on memory, immediately after compression and one week later. A series of baseline parameters were also captured including compression force, breast size/density, menstrual history and any adverse events following mammography to allow the investigation of relationships. RESULTS: There was a strong correlation (r = 0.79, p < 0.001) between previous pain scores and current pain scores, no significant correlations were found between breast size, breast density or total compression force and pain. Pain scores reduced between previous and current examinations and there was consistency in overall pain scores, despite variations in the compression forces applied. CONCLUSION: Physical side effects from mammography can develop and extend beyond the examination period. Patients' prior experience of pain was the only significant predictor of current pain in this study. IMPLICATIONS FOR PRACTICE: Data on past mammography experiences are essential to improve future pain outcomes. Post-mammography aftercare should be a routine feature of the examination.

Effective lifetime radiation risk for a number of national mammography screening programmes.

BACKGROUND AND PURPOSE: The performance of mammography screening programmes is focussed mainly on breast cancer detection rates. However, when the benefits and risks of mammography are considered, the risk of radiation-induced cancer is calculated for only the examined breast using Mean Glandular Dose (MGD). The risk from radiation during mammography is often described as low or minimal. This study aims to evaluate the effective lifetime risk from full field digital mammography (FFDM) for a number of national screening programmes. MATERIAL AND METHODS: Using an ATOM phantom, radiation doses to multiple organs were measured during standard screening mammography. Sixteen FFDM machines were used and the effective lifetime risk was calculated across the female lifespan for each machine. Once the risks were calculated using the phantom, the total effective lifetime risk across 48 national screening programmes was then calculated; this assumed that all these programmes use FFDM for screening. RESULTS: Large differences exist in effective lifetime risk, varying from 42.21 [39.12-45.30] cases/106 (mean [95% CI]) in the Maltese screening programme to 1099.67 [1019.25-1180.09] cases/106 for high breast cancer risk women in the United States of America. These differences are mainly attributed to the commencement age of screening mammography and the time interval between successive screens. CONCLUSIONS: Effective risk should be considered as an additional parameter for the assessment of screening mammography programme performance, especially for those programmes which recommend an early onset and more frequent screening mammography.

Estimating the error of CT-based measurements of aortic lumen volume used in endovascular planning.

INTRODUCTION: Planning of endovascular sealing of abdominal aortic aneurysms requires measurement of the aortic lumen volume. The aim of this study was to investigate mathematically the effect of intra- and inter-observer variability error, as well as cardiac cycle-related variability, on these measurements. METHODS: Mean (±2SD) intra- and inter-observer error in lumen measurements and mean (+2SD) cardiac cycle-related variability were obtained from published literature and added to the measurement of the flow lumen volume of a 57 mm abdominal aortic aneurysm to calculate average and extreme error possibilities. RESULTS: The aneurysm volume was measured at 165 ml. The calculated possible mean measurement error due to cardiac cycle variation, intra- and inter-observer variability was +11.0%, resulting in a potential measurement of 183.1 ml. The calculated extreme errors were +24.3% (if 2SD of all errors were added to the mean) and +3.5% (if 2SD of all errors, except cardiac cycle, were subtracted from the mean), resulting in potential measurements of 170.8 ml and 205.1 ml, respectively. When considering the errors combined, the proportion of patients who may have volume measurement errors of up to ±2.5 ml, ±2.6 to ±5.0 ml and ±5.1 to ±7.5 ml were 18%, 17% and 15%, respectively. CONCLUSION: Measurement of CT-based aortic lumen volumes in abdominal aortic aneurysms is imprecise. This has practical implications for the planning and the performance of complex endovascular therapies.

Antero-posterior (AP) pelvis x-ray imaging on a trolley: Impact of trolley design, mattress design and radiographer practice on image quality and radiation dose.

INTRODUCTION: Physical and technical differences exist between imaging on an x-ray tabletop and imaging on a trolley. This study evaluates how trolley imaging impacts image quality and radiation dose for an antero-posterior (AP) pelvis projection whilst subsequently exploring means of optimising this imaging examination. METHODS: An anthropomorphic pelvis phantom was imaged on a commercially available trolley under various conditions. Variables explored included two mattresses, two image receptor holder positions, three source to image distances (SIDs) and four mAs values. Image quality was evaluated using relative visual grading analysis with the reference image acquired on the x-ray tabletop. Contrast to noise ratio (CNR) was calculated. Effective dose was established using Monte Carlo simulation. Optimisation scores were derived as a figure of merit by dividing effective dose with visual image quality scores. RESULTS: Visual image quality reduced significantly (p < 0.05) whilst effective dose increased significantly (p < 0.05) for images acquired on the trolley using identical acquisition parameters to the reference image. The trolley image with the highest optimisation score was acquired using 130 cm SID, 20 mAs, the standard mattress and platform not elevated. A difference of 12.8 mm was found between the image with the lowest and highest magnification factor (18%). CONCLUSION: The acquisition parameters used for AP pelvis on the x-ray tabletop are not transferable to trolley imaging and should be modified accordingly to compensate for the differences that exist. Exposure charts should be developed for trolley imaging to ensure optimal image quality at lowest possible dose.

Virtual reality, ultrasound-guided liver biopsy simulator: development and performance discrimination.

OBJECTIVES: The aim of this article was to identify and prospectively investigate simulated ultrasound-guided targeted liver biopsy performance metrics as differentiators between levels of expertise in interventional radiology. METHODS: Task analysis produced detailed procedural step documentation allowing identification of critical procedure steps and performance metrics for use in a virtual reality ultrasound-guided targeted liver biopsy procedure. Consultant (n=14; male=11, female=3) and trainee (n=26; male=19, female=7) scores on the performance metrics were compared. Ethical approval was granted by the Liverpool Research Ethics Committee (UK). Independent t-tests and analysis of variance (ANOVA) investigated differences between groups. RESULTS: Independent t-tests revealed significant differences between trainees and consultants on three performance metrics: targeting, p=0.018, t=-2.487 (-2.040 to -0.207); probe usage time, p = 0.040, t=2.132 (11.064 to 427.983); mean needle length in beam, p=0.029, t=-2.272 (-0.028 to -0.002). ANOVA reported significant differences across years of experience (0-1, 1-2, 3+ years) on seven performance metrics: no-go area touched, p=0.012; targeting, p=0.025; length of session, p=0.024; probe usage time, p=0.025; total needle distance moved, p=0.038; number of skin contacts, p<0.001; total time in no-go area, p=0.008. More experienced participants consistently received better performance scores on all 19 performance metrics. CONCLUSION: It is possible to measure and monitor performance using simulation, with performance metrics providing feedback on skill level and differentiating levels of expertise. However, a transfer of training study is required.