Eye radiation dose from breast cancer screening using full field digital mammography and digital breast tomosynthesis: A phantom study.

INTRODUCTION: The eye lens is recently classified as one of the most radiosensitive tissues by the International Commission on Radiological Protection (ICRP), and it has been suggested that the eye lens receives radiation dose during mammography due to scatter radiation. The aim of this study was to investigate the radiation dose received by the lens of the clients' eye from Full Field Digital Mammography (FFDM) and Digital Breast Tomosynthesis (DBT) screening. METHODS: The eye radiation dose received by ATOM dosimetry phantom was estimated with thermo-luminescent dosemeters (TLDs). One TLD was utilised for each eye. A breast phantom was exposed for four-view screening mammography using 16 FFDM machines and one DBT machine. The breast phantom was exposed three times for each mammographic position and an average TLD dose reading was considered to minimise random error. RESULTS: For four-view FFDM screening, the phantom eye radiation dose ranges from 0.013 mGy to 0.029 mGy with a mean±sd of 0.019 ± 0.005 mGy. A higher eye radiation dose of 0.041 mGy was recorded from four-view DBT screening. The statistical analysis demonstrated that the eye lens radiation dose is strongly and significantly correlated to breast organ dose and X-ray tube voltage. CONCLUSION: The phantom eye lens was exposed to scatter radiation from FFDM and DBT screening. The measured dose via the four-view DBT screening was higher than the four-view FFDM screening, but sits below the internationally acceptable ranges. If the findings of our paper hold true in practice, then the risk to the lens of the eyes for women attending breast screening is acceptable. IMPLICATIONS FOR PRACTICE: The new lens radiation dose levels recommended by the ICRP necessitate the reevaluation of eye radiation dose from different radiographic examinations, especially those used for screening purpose where healthy individuals involved.

Rapid creation of a website to produce educational and clinical support resources for global use during and beyond the COVID-19 pandemic.

It became clear at the onset of the pandemic that radiography could play an important role in diagnosing and staging COVID-19. The key modality would be mobile chest radiography. However, at the onset of the pandemic, no literature existed to indicate whether or not chest X-ray imaging could be used effectively to diagnose or exclude COVID-19. This article explains how a website was created, at speed, during the initial phase of the COVID-19 pandemic. Containing holistic information, the website helped enable rapid redeployment of radiographers onto the frontline where chest X-ray imaging was needed. It aimed to help train radiographers take (and interpret) chest radiographs in high-risk areas that contained large numbers of COVID-19 patients. Within one year, the website had been used in 157 countries. This article documents the approach taken to create the website and suggestions are made about how, in the future, a rapid approach could be achieved to create other websites - should an international crisis occur again. This paper also outlines how stakeholders and content authors from across the world were brought together and supported to create the website. It goes on to explain the leadership style that was adopted to create the website and why that style was selected. An explanation is offered about the project management approach and how its ingredients relate to a published model. Aside from simply providing a historical account of how the website was created, we hope the narrative offers food for thought on how to respond rapidly during an international crisis to formulate and implement a unified international-level solution which addresses an urgent need.

Interprofessional research teams in radiography - where the magic happens.

Based on publications and professional experiences, this article, intended for academic and clinical therapy/diagnostic radiographers, considers conducting research in interprofessional teams, including its values and how to go about achieving it. Whilst there is a growing number of journal papers published by interprofessional teams, almost nothing is published about how best to build interprofessional research relationships or harness the potential of the different professional experience to deliver novel research within the radiography literature. Thus, this article draws heavily on our experiences of creating, working within and leading interprofessional teams which have a specific focus on conducting radiography-related research. Suggestions are proposed about how to create an interprofessional research team and how to get the best out of it. Values of working within an interprofessional research team, to self, to research quality and to the end users of the research are considered.

The impact of teaching experimental research on-line: Research-informed teaching and COVID-19.

INTRODUCTION: As part of the BSc (Hons) Diagnostic Radiography programme students learn and undertake research relevant to their development as first post radiographers (dose optimisation and image quality) within the Research-Informed Teaching experience (RiTe). Due to the COVID-19 pandemic, the delivery of RiTe to our year 2 students was moved to an online format using Microsoft Teams and Blackboard Collaborate and focused on a key area of current practice - COVID-19 and chest X-ray imaging. Within RiTe students are placed into collaborative enquiry-based learning (CEBL) groups to share tasks, but to also support and learn from one another. METHODS: An online survey was used to explore the year 2 student cohort task value and self-efficacy of this online version of RiTe. RESULTS: A 73% (32/44) response rate was achieved. Students found the online version of RiTe to be a positive learning and development experience. There was strong agreement that they not only found it relevant to their area of practice (task-value), but also strongly agreed that they understood and could master the skills taught (self-efficacy). CONCLUSION: This online version of RiTe was effectively structured to help scaffold student learning and development of research data analysis skills despite the lack of face-to-face teaching. The students also valued the topic area (COVID-19 and chest X-ray imaging). A blended learning approach with RiTe will be used next year with a combination of collaborative online teaching and physical data collection and analysis in the university-based X-ray imaging laboratory. Further evaluation and data collection will also be undertaken. IMPLICATIONS FOR PRACTICE: University-based empirical work in groups to learn about research can be replaced by an online mechanism whilst still maintaining task-value and acceptable self-efficacy.

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

INTRODUCTION: Mattresses 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. METHODS: Thirteen 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 (IQFinv) using a commercially available phantom (CDRAD) for the same exposure factors. The correlation of age and attenuation and image quality was calculated. RESULTS: Measured 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. IQFinv 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. CONCLUSION: The 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 PRACTICE: Quality 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.

Compression force variability in mammography in Ghana - A baseline study.

INTRODUCTION: Breast compression during mammographic examinations improves image quality and patient management. Several studies have been conducted to assess compression force variability among practitioners in order to establish compression guidelines. However, no such study has been conducted in Ghana. This study aims to investigate the compression force variability in mammography in Ghana. METHODS: This retrospective study used data gathered from 1071 screening and diagnostic mammography patients from January, 2018-December, 2019. Data were gathered by seven radiographers at three centers. Compression force, breast thickness and practitioners' years of work experience were recorded. Compression force variability among practitioners and the correlation between compression force and breast thickness were investigated. RESULTS: Mean compression force values recorded for craniocaudal (CC) (17.2 daN) and mediolateral oblique (MLO) (18.2 daN), were within the recommended values used by western countries. Most of the mammograms performed - 80% - were within the National Health Service Breast Screening Programme (NHSBSP) range. However, 65% were above the Norwegian Breast Cancer Screening Programme (NBCSP) range. Compression forces varied significantly (p = 0.0001) among practitioners. Compression forces increased significantly (p = 0.0001) with the years of work experience. A weak negative correlation (r = -0.144) and a weak positive correlation (r = 0.142) were established between compression force and breast thickness for CC and MLO projections respectively. CONCLUSION: This initial study confirmed that although wide variations in compression force exist among practitioners in Ghana, most practitioners used compression forces broadly within the range set by the NHSBSP. As no national guidelines for compression force currently exist in Ghana, provision of these may help to reduce the range of variations recorded. IMPLICATIONS FOR PRACTICE: Confirmation of variations in compression will guide future practice to minimize image quality disparities and improve quality of care.

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.

Development and validation of a bespoke phantom to test accuracy of Cobb angle measurements.

INTRODUCTION: Adolescent idiopathic scoliosis (AIS) is a spinal deformity that causes the spine to bend laterally. Patients with AIS undergo frequent X-ray examinations to monitor the progression of the disorder by through the measurement of the Cobb angle. Frequent exposure of adolescents poses the risk of radiation-induced cancer. The aim of this research was to design and build a bespoke phantom representing a 10-year-old child with AIS to allow optimisation of imaging protocols for AIS assessment through the accuracy of Cobb angle measurements. METHODS: Poly-methyl methacrylate (PMMA) and plaster of Paris (PoP) were used to represent human soft tissue and bone tissue, respectively, to construct a phantom exhibiting a 15° lateral curve of the spine. The phantom was validated by comparing the Hounsfield unit (HU) of its vertebrae with that of human and sheep. Additionally, comparisons of signal-to-noise ratio (SNR) to those from a commercially available phantom. An assessment of the accuracy of the radiographic assessment of the Cobb angle measurement was performed. RESULTS: The HU of the PoP vertebrae was 628 (SD = 56), human vertebrae was 598 (SD = 79) and sheep vertebra was 605 (SD = 83). The SNR values of the two phantoms correlated strongly (r = 0.93 (p = 0.00)). The measured scoliosis angle was 14°. CONCLUSION: The phantom has physical characteristics (in terms of spinal deformity) and radiological characteristics (in terms of HU and SNR values) of the spine of a 10-year-old child with AIS. This phantom has utility for the optimisation of x-ray imaging techniques in 10 year old children. IMPLICATIONS FOR PRACTICE: A phantom to investigate new x-ray imaging techniques and technology in the assessment of scoliosis and to optimise currently used protocols.

The accuracy of Cobb angle measurement on CT scan projection radiograph images.

INTRODUCTION: Adolescent idiopathic scoliosis (AIS) is a spinal deformity that can affect young children. It requires frequent exposure to X-rays to monitor the deformity, which can lead to the development of radiation-induced cancer later in life. The aim of this study is to test the accuracy of using scan projection radiography (SPR) in computed tomography (CT) scans for AIS assessment. This scanning mode delivers low radiation compared with conventional radiography. METHOD: A bespoke phantom with a 14° scoliotic spine was scanned in CT SPR mode using 18 imaging acquisitions. These images were visually evaluated against set criteria to determine their suitability for Cobb angle measurements Those deemed of insufficient quality were excluded from the study (n = 8, excluded). Cobb angle measurements were then performed on the remaining images (n = 10, included) by 13 observers. RESULTS: On average, the difference between the measured Cobb angle and the known angle was -2.75° (SD 1.46°). The agreement between the observers was good (p = 0.861, 95% CI 0.70-0.95) and comparable to similar studies on other imaging modalities which are used for Cobb angle estimation. CONCLUSION: CT SPR images can be used for AIS assessment with the 5° margin of error that is clinically acceptable. IMPLICATIONS FOR PRACTICE: The outcome is promising for patients and health providers because it provides an opportunity to reduce patient dose, achieve clinically acceptable Cobb angle measurements whilst using existing (CT) technology that is available in most hospital.

Video rasterstereography of the spine and pelvis in eight erect positions: A reliability study.

INTRODUCTION: To investigate the reliability and variability of Video Rasterstereography (VR) measurements of the spine and pelvis, for eight proposed standing postures, in order to help define an optimal standing position for erect pelvis radiography. METHODS: Surface topography data were collected using the formetic 4D dynamic modelling (Diers) system. 61 healthy participants were recruited; each participant performed eight different standing positions. Four positions were performed with the feet shoulder width apart and parallel, and four positions were performed with the feet shoulder width apart and internally rotated. For the upper extremity, each of the (two sets of) four positions were performed with different arm positions (arms by the sides, arms crossed over the chest, arms 30° flexed and touching the medial end of the clavicle, arms 30° flexed with the hands holding a support). Three sets of surface topography were collected in the eight positions (n = 24). The variability was assessed by calculating standard error of the measurement (SEm) and the coefficient of variation (CV). Reliability was assessed using intra-class correlation coefficients (ICC ± 95% CI). RESULTS: No significant differences in the SEm were found between the three paired measurements for all standing positions (P > 0.05). ICC values demonstrated excellent reliability for all measurements across the eight standing positions (range 0.879-1.00 [95% CI 0.813-1.00]). CONCLUSION: Evaluating eight standing positions radiographically would be unethical as it would involve repeat radiation exposures. Using the formetic 4D dynamic modelling (Diers) system, provides an alternative and has shown that there was only a minimal, non-statistically significant, differences between the eight different standing positions. IMPLICATION FOR PRACTICE: Different standing positions were proposed for erect pelvis radiography.

Radiation protection value to the operator from augmented reality smart glasses in interventional fluoroscopy procedures using phantoms.

INTRODUCTION: Smart glasses can be adapted to display radiographic images to allow clinician's gaze not to be directionally fixed or predetermined by computer monitor location. This study presents an analysis of eye lens dose during interventional fluoroscopy guided procedures, comparing fixed monitor positions against the use of smart glasses. METHODS: Using a head phantom (simulating the clinician), thermoluminescent dosimeters and lead shielded glasses, the dose to the eye was measured for different head 'rotations and tilts' for: gaze directed towards the main scattering source (patient/primary beam) to represent potential gaze direction if smart glasses are used; gaze directed to a range of potential computer monitor positions. An anthropomorphic pelvis phantom was utilised to simulate the patient. Accumulated dose rates (µGy s-1) from five 10-second exposures at 75 kV 25.2 mAs were recorded. RESULTS: An average DAP reading of 758.84 cGy cm2 was measured during each 10 second exposure. Whilst wearing lead shielded glasses a 6.10 - fold reduction in dose rate to the lens is possible (p < 0.05). Influence of the direction of gaze by the clinician demonstrated a wide range of dose rate reduction from 3.13% (p = 0.16) to 143.69% (p < 0.05) when the clinician's gaze was towards the main scattering source. Increased dose rate to the clinician's eyes was received despite wearing lead shielded glasses, as the angle of gaze moved 45° and 90° from 0°. CONCLUSION: If the clinician's gaze is directed towards the main scattering source a potential exists for reducing eye lens dose compared with fixed location computer monitors. Introduction of lead lined smart glasses into interventional radiology may lead to improvements in patient care, reducing the need for the clinician to look away from the patient to observe a radiographic image.

Radiographers' perspectives' on Visual Grading Analysis as a scientific method to evaluate image quality.

INTRODUCTION: Radiographers routinely undertake many initiatives to balance image quality with radiation dose (optimisation). For optimisation studies to be successful image quality needs to be carefully evaluated. Purpose was to 1) discuss the strengths and limitations of a Visual Grading Analysis (VGA) method for image quality evaluation and 2) to outline the method from a radiographer's perspective. METHODS: A possible method for investigating and discussing the relationship between radiographic image quality parameters and the interpretation and perception of X-ray images is the VGA method. VGA has a number of advantages such as being low cost and a detailed image quality assessment, although it is limited to ensure the images convey the relevant clinical information and relate the task based radiography. RESULTS: Comparing the experience of using VGA and Receiver Operating Characteristic (ROC) it is obviously that less papers are published on VGA (Pubmed n=1.384) compared to ROC (Pubmed n=122.686). Hereby the scientific experience of the VGA method is limited compared to the use of ROC. VGA is, however, a much newer method and it is slowly gaining more and more attention. CONCLUSION: The success of VGA requires a number of steps to be completed, such as defining the VGA criteria, choosing the VGA method (absolute or relative), including observers, finding the best image display platforms, training observers and selecting the best statistical method for the study purpose should be thoroughly considered. IMPLICATION FOR PRACTICE: Detailed evaluation of image quality for optimisation studies related to technical definition of image quality.

Scoliosis imaging: An analysis of radiation risk in the CT scan projection radiograph and a comparison with projection radiography and EOS.

INTRODUCTION: Scoliosis is defined as a deformity of the spine with lateral curvature in the coronal plane. It requires regular X-ray imaging to monitor the progress of the disorder, therefore scoliotic patients are frequently exposed to radiation. It is important to lower the risk from these exposures for young patients. The aim of this work is to compare organ dose (OD) values resulting from Scan Projection Radiograph (SPR) mode in CT against projection radiography and EOS® imaging system when assessing scoliosis. METHODS: A dosimetry phantom was used to represent a 10-year old child. Thermoluminescent dosimetry detectors were used for measuring OD. The phantom was imaged with CT in SPR mode using 27 imaging parameters; projection radiography and EOS machines using local scoliosis imaging procedures. Imaging was performed in anteroposterior, posteroanterior and lateral positions. RESULTS: 17 protocols delivered significantly lower radiation dose than projection radiography (p < 0.05). OD values from the CT SPR imaging protocols and projection radiography were statistically significant higher than the results from EOS. No statistically significant differences in OD were observed between 10 imaging protocols and those from projection radiography and EOS imaging protocols (p > 0.05). CONCLUSION: EOS has the lowest dose. Where this technology is not available we suggest there is a potential for OD reduction in scoliosis imaging using CT SPR compared to projection radiography. Further work is required to investigate image quality in relation to the measurement of Cobb angle with CT SPR.

Impact of body part thickness on AP pelvis radiographic image quality and effective dose.

INTRODUCTION: Within medical imaging variations in patient size can generate challenges, especially when selecting appropriate acquisition parameters. This experiment sought to evaluate the impact of increasing body part thickness on image quality (IQ) and effective dose (E) and identify optimum exposure parameters. METHODS: An anthropomorphic pelvis phantom was imaged with additional layers (1-15 cm) of animal fat as a proxy for increasing body thickness. Acquisitions used the automatic exposure control (AEC), 100 cm source to image distance (SID) and a range of tube potentials (70-110 kVp). IQ was evaluated physically and perceptually. E was estimated using PCXMC software. RESULTS: For all tube potentials, signal to noise ratio (SNR) and contrast to noise ratio (CNR) deceased as body part thickness increased. 70 kVp produced the highest SNR (46.6-22.6); CNR (42.8-17.6). Visual grading showed that the highest IQ scores were achieved using 70 and 75 kVp. As thickness increases, E increased exponentially (r = 0.96; p < 0.001). Correlations were found between visual and physical IQ (SNR r = 0.97, p < 0.001; CNR r = 0.98, p < 0.001). CONCLUSION: To achieve an optimal IQ across the range of thicknesses, lower kVp settings were most effective. This is at variance with professional practice as there is a tendency for radiographers to increase kVp as thickness increases. Dose reductions were experienced at higher kVp settings and are a valid method for optimisation when imaging larger patients.

Protein disulfide isomerase regulation by nitric oxide maintains vascular quiescence and controls thrombus formation.

Essentials Nitric oxide synthesis controls protein disulfide isomerase (PDI) function. Nitric oxide (NO) modulation of PDI controls endothelial thrombogenicity. S-nitrosylated PDI inhibits platelet function and thrombosis. Nitric oxide maintains vascular quiescence in part through inhibition of PDI. SUMMARY: Background Protein disulfide isomerase (PDI) plays an essential role in thrombus formation, and PDI inhibition is being evaluated clinically as a novel anticoagulant strategy. However, little is known about the regulation of PDI in the vasculature. Thiols within the catalytic motif of PDI are essential for its role in thrombosis. These same thiols bind nitric oxide (NO), which is a potent regulator of vessel function. To determine whether regulation of PDI represents a mechanism by which NO controls vascular quiescence, we evaluated the effect of NO on PDI function in endothelial cells and platelets, and thrombus formation in vivo. Aim To assess the effect of S-nitrosylation on the regulation of PDI and other thiol isomerases in the vasculature. Methods and results The role of endogenous NO in PDI activity was evaluated by incubating endothelium with an NO scavenger, which resulted in exposure of free thiols, increased thiol isomerase activity, and enhanced thrombin generation on the cell membrane. Conversely, exposure of endothelium to NO+ carriers or elevation of endogenous NO levels by induction of NO synthesis resulted in S-nitrosylation of PDI and decreased surface thiol reductase activity. S-nitrosylation of platelet PDI inhibited its reductase activity, and S-nitrosylated PDI interfered with platelet aggregation, α-granule release, and thrombin generation on platelets. S-nitrosylated PDI also blocked laser-induced thrombus formation when infused into mice. S-nitrosylated ERp5 and ERp57 were found to have similar inhibitory activity. Conclusions These studies identify NO as a critical regulator of vascular PDI, and show that regulation of PDI function is an important mechanism by which NO maintains vascular quiescence.