Trends in pre-hospital volume resuscitation of blunt trauma patients: a 15-year analysis of the British (TARN) and German (TraumaRegister DGU®) National Registries.

INTRODUCTION: Fluid resuscitation has long been a cornerstone of pre-hospital trauma care, yet its optimal approach remains undetermined. Although a liberal approach to fluid resuscitation has been linked with increased complications, the potential survival benefits of a restrictive approach in blunt trauma patients have not been definitively established. Consequently, equipoise persists regarding the optimal fluid resuscitation strategy in this population. METHODS: We analysed data from the two largest European trauma registries, the UK Trauma Audit and Research Network (TARN) and the German TraumaRegister DGU® (TR-DGU), between 2004 and 2018. All adult blunt trauma patients with an Injury Severity Score > 15 were included. We examined annual trends in pre-hospital fluid resuscitation, admission coagulation function, and mortality rates. RESULTS: Over the 15-year study period, data from 68,510 patients in the TARN cohort and 82,551 patients in the TR-DGU cohort were analysed. In the TARN cohort, 3.4% patients received pre-hospital crystalloid fluids, with a median volume of 25 ml (20-36 ml) administered. Conversely, in the TR-DGU cohort, 91.1% patients received pre-hospital crystalloid fluids, with a median volume of 756 ml (750-912 ml) administered. Notably, both cohorts demonstrated a consistent year-on-year decrease in the volume of pre-hospital fluid administered, accompanied by improvements in admission coagulation function and reduced mortality rates. CONCLUSION: Considerable variability exists in pre-hospital fluid resuscitation strategies for blunt trauma patients. Our data suggest a trend towards reduced pre-hospital fluid administration over time. This trend appears to be associated with improved coagulation function and decreased mortality rates. However, we acknowledge that these outcomes are influenced by multiple factors, including other improvements in pre-hospital care over time. Future research should aim to identify which trauma populations may benefit, be harmed, or remain unaffected by different pre-hospital fluid resuscitation strategies.

Cylindrical ionization chamber response in static and dynamic 6 and 15 MV photon beams.

Purpose.To investigate the response of the CC13 ionization chamber under non-reference photon beam conditions, focusing on penumbra and build-up regions of static fields and on dynamic intensity-modulated beams.Methods. Measurements were performed in 6 MV 100 × 100, 20 × 100, and 20 × 20 mm2static fields. Monte Carlo calculations were performed for the static fields and for 6 and 15 MV dynamic beam sequences using a Varian multi-leaf collimator. The chamber was modelled using EGSnrc egs_chamber software. Conversion factors were calculated by relating the absorbed dose to air in the chamber air cavity to the absorbed dose to water. Correction and point-dose correction factors were calculated to quantify the conversion factor variations.Results. The correction factors for positions on the beam central axis and at the penumbra centre were 0.98-1.02 for all static fields and depths investigated. The largest corrections were obtained for chamber positions beyond penumbra centre in the off-axis direction. Point-dose correction factors were 0.54-0.71 at 100 mm depth and their magnitude increased with decreasing field size and measurement depth. Factors of 0.99-1.03 were obtained inside and near the integrated penumbra of the dynamic field at 100 mm depth, and of 0.92-0.94 beyond the integrated penumbra centre. The variations in the ionization chamber response across the integrated dynamic penumbra qualitatively followed the behaviour across penumbra of static fields.Conclusions. Without corrections, the CC13 chamber was of limited usefulness for profile measurements in 20-mm-wide fields. However, measurements in dynamic small irregular beam openings resembling the conditions of pre-treatment patient quality assurance were feasible. Uncorrected ionization chamber response could be applied for dose verification at 100 mm depth inside and close to large gradients of dynamically accumulating high- and low-dose regions assuming 3% tolerance between measured and calculated doses.

Surgical site infections: a scoping review on current intraoperative prevention measures.

INTRODUCTION: Surgical site infections (SSIs) remain a significant cause of morbidity for surgical patients worldwide and with growing rates of antibiotic resistance, the development of new nonantimicrobial techniques to target SSI reduction is crucial. This review aimed to explore available nonantibiotic intraoperative interventions to reduce the risk of SSI. METHODS: A literature search was undertaken using Medline, Web of Science, Embase, and Cochrane Library databases. Any study published from 1 January 1980 to 1 September 2021 that described any nonantibiotic intraoperative physical technique aiming to reduce SSI rates, with a primary or secondary outcome of SSI rates, was included. FINDINGS: A total of 45 articles were included in the final scoping review. The current nonantibiotic intraoperative interventions advised for use include chlorhexidine skin preparation with alcohol, pressurised wound irrigation, Triclosan-coated sutures for skin closure, and negative pressure wound therapy. Many other widely used surgical practices do not have the supporting evidence to validate their routine use in clinical practice to reduce SSI rates. CONCLUSIONS: We identified several techniques that can be used in the operating theatre to provide additional opportunities to reduce SSI rates. However, strict adherence to current established SSI prevention guidelines remains the mainstay of ensuring SSI rates remain low.

Does pulsed lavage reduce the risk of surgical site infection? A systematic review and meta-analysis.

BACKGROUND: Surgical site infections (SSIs) remain a significant and common postoperative complication. Whereas most surgeons use some form of wound irrigation during closure, its impact on SSI rates is debated. Preliminary studies in the use of pressurized irrigation, termed pulsed lavage, may have potential benefit to reduce the risk of SSI. AIM: To perform a systematic review to identify studies that reported SSI rates following surgery, comparing the use of pulsed lavage to controls, following PRISMA guidelines. METHODS: All study types and those published up to January 1st, 2021 were included. Odds ratios (ORs) were calculated for each included study using a Mantel-Haenszel statistical analysis, via a random effects model. A sub-analysis on abdominal procedures only was also performed. FINDINGS: Eleven studies met the inclusion criteria, covering either orthopaedic or general surgery procedures; 1875 patients were included, with 816 patients in the pulsed lavage group and 1059 patients in the control group. Overall study quality was low. There was a significant reduction in the SSI rate with the use of pulsed lavage (odds ratio (OR): 0.39; 95% confidence interval (CI): 0.25-0.62; P < 0.0001). Sub-analysis on abdominal operations only showed further improvement to the SSI rate with pulsed lavage (OR: 0.32; 95% CI: 0.21-0.49; P < 0.0001). CONCLUSION: Pulsed lavage significantly reduces the rate of SSIs in surgical procedures, the effect being most pronounced in abdominal operations; however, current study quality is low. Randomized controlled trial data are essential to fully assess the potential clinical and financial benefits pulsed lavage can confer to SSI reduction.

Burnout within UK surgical specialties: a systematic review.

INTRODUCTION: Burnout is of growing concern within the surgical workforce, having been shown to result in reduced job satisfaction, decreased patient satisfaction and higher rates of medical errors. Determining the extent of burnout and identifying its risk factors within UK surgical practice is essential to ensure appropriate interventions can be implemented to improve mental wellbeing. MATERIALS: A systematic search of PubMed, Medline, Embase, PsychINFO and Cochrane databases was performed, following PRISMA guidelines. Studies published between January 2000 and October 2019 that reported prevalence data or risk factors on burnout for surgeons working within the UK and/or the Republic of Ireland were included. FINDINGS: Ten papers met the inclusion criteria. The overall prevalence of burnout amongst surgeons in the UK was 32.0% (IQR 28.9-41.0%), with surgical trainees having the highest prevalence (59.0%) of burnout documented for any subgroup. The most common risk factors identified for burnout were younger surgeon age and lower clinical grade. Being married or living with a partner was found to be protective. CONCLUSIONS: Burnout is highly prevalent in UK surgical specialties, mostly amongst surgical trainees. Targeted pre-emptive interventions based upon relevant risk factors for burnout should be prioritised, at both individual and institutional levels.

A MODEL FOR EVALUATING THE USE OF IMAGING IN IMAGE-GUIDED INTERVENTIONAL PROCEDURES-POSSIBLE IMPLICATIONS ON OPTIMISATION OF RADIATION PROTECTION.

The present study focuses on introducing the concept of optimisation and proposing a model, including evaluation of image quality, to be used in the clinical routines where image-guided intervention is being performed. The overall aim of the study was to develop a model for evaluating the use of imaging in X-ray-guided interventional procedures and its possible implications on optimisation of radiation protection. In the search for an adequate evaluation model, data from endovascular interventions of the aorta (EVAR procedures) were used. The procedure was schematically described in steps. Every imaging event was connected to the steps in the medical procedure and was also described with the purpose of the imaging event. Available technical, as well as procedural parameters, were studied and analysed. Data were collected from the X-ray equipment for 70 EVAR procedures and, out of these, 12 procedures were randomly selected to be recorded on video to understand the procedure better. It was possible to describe the EVAR procedures in a general way with explanations of the clinical purpose connected to each imaging event. Possible quality parameters of the procedure were identified for the imaging events (radiation dose, image quality). The model method still needs to be refined and will then be applied to clinical data and to other clinical procedures to test the validity.

QUANTIFICATION OF PULMONARY PATHOLOGY IN CYSTIC FIBROSIS-COMPARISON BETWEEN DIGITAL CHEST TOMOSYNTHESIS AND COMPUTED TOMOGRAPHY.

PURPOSE: Digital tomosynthesis (DTS) is currently undergoing validation for potential clinical implications. The aim of this study was to investigate the potential for DTS as a low-dose alternative to computed tomography (CT) in imaging of pulmonary pathology in patients with cystic fibrosis (CF). METHODS: DTS and CT were performed as part of the routine triannual follow-up in 31 CF patients. Extent of disease was quantified according to modality-specific scoring systems. Statistical analysis included Spearman's rank correlation coefficient (r) and Krippendorff's alpha (α). MAJOR FINDINGS: The median effective dose was 0.14 for DTS and 2.68 for CT. Intermodality correlation was very strong for total score and the subscores regarding bronchiectasis and bronchial wall-thickening (r = 0.82-0.91, P < 0.01). Interobserver reliability was high for total score, bronchiectasis and mucus plugging (α = 0.83-0.93) in DTS. CONCLUSION: Chest tomosynthesis could be a low-dose alternative to CT in quantitative estimation of structural lung disease in CF.

Challenges assessing radiation risk in image-guided treatments-implications on optimisation of radiological protection.

The present work explores challenges when assessing organ dose and effective dose concerning image-guided treatments. During these treatments considerable x-ray imaging is employed using technically advanced angiographic x-ray equipment. Thus, the radiation dose to organs and the related radiation risk are relatively difficult to assess. This has implications on the optimisation process, in which assessing radiation dose is one important part. In this study, endovascular aortic repair treatments were investigated. Organ dose and effective dose were assessed using Monte Carlo calculations together with a detailed specification of the exposure situation and patient size. The resulting normalised organ dose and effective dose with respect to kerma-area product for patient sizes and radiation qualities representative for the patient group were evaluated. The variability and uncertainty were investigated and their possible impact on optimisation of radiation protection was discussed. Exposure parameters, source to detector distances etc varied between treatments and also varied between image acquisitions during one treatment. Thus the derived normalised organ dose and effective dose exhibited a large range of values depending greatly on used exposure parameters and patient configuration. The derived normalised values for effective dose varied approximately between 0.05 and 0.30 mSv per Gy·cm2 when taking patient sizes and exposure parameters into consideration, the values for organ doses exhibited even larger variation. The study shows a possible systematic error for derived organ doses and effective dose up to a factor of 7 if detailed exposure or patient characteristics are not known and/or not taken into consideration. The intra-treatment variability was also substantial and the normalised dose values varied up to a factor of 2 between image acquisitions during one treatment. The study shows that the use of conversion factors that are not adapted to the clinic can cause the radiation dose to be exaggerated or underestimated considerably. A conclusion from the present study is that the systematic error could be large and should be estimated together with random errors. A large uncertainty makes it difficult to detect true differences in radiation dose between methods and technology-a prerequisite for optimising radiation protection for image-guided treatments.

Impact of abdominal aortic aneurysm screening on quality of life.

BACKGROUND: Screening for abdominal aortic aneurysm (AAA) is known to reduce AAA-related mortality; however, the psychological impact of population AAA screening is unclear. The aim was to assess the impact of AAA diagnosis on quality of life (QoL) using data from an established AAA screening programme. METHODS: Mental and physical QoL scores for men diagnosed with AAA through participation in the English and Welsh AAA screening programmes were compared with no-AAA controls. Participants were identified through the United Kingdom Aneurysm Growth Study (UKAGS), a nationwide prospective cohort study of men with an AAA of less than 55 mm diagnosed through voluntary participation in screening. The UKAGS participants completed QoL questionnaires at the time of screening and annually thereafter. RESULTS: A transient reduction in mental QoL scores was observed following the diagnosis of AAA, returning to baseline levels after 12 months. Physical QoL remained consistently lower in the AAA cohort. Participants thought about their AAA and the AAA growth progressively less 12 months after the initial screening diagnosis. AAA growth rate had no influence over QoL parameters. DISCUSSION: This study suggests that screening for AAA does reduce mental QoL; however, this effect is transient (less than 12 months). Men diagnosed with AAA have a consistently worse physical QoL compared with controls.

Fast GPU-based Monte Carlo code for SPECT/CT reconstructions generates improved 177Lu images.

BACKGROUND: Full Monte Carlo (MC)-based SPECT reconstructions have a strong potential for correcting for image degrading factors, but the reconstruction times are long. The objective of this study was to develop a highly parallel Monte Carlo code for fast, ordered subset expectation maximum (OSEM) reconstructions of SPECT/CT images. The MC code was written in the Compute Unified Device Architecture language for a computer with four graphics processing units (GPUs) (GeForce GTX Titan X, Nvidia, USA). This enabled simulations of parallel photon emissions from the voxels matrix (1283 or 2563). Each computed tomography (CT) number was converted to attenuation coefficients for photo absorption, coherent scattering, and incoherent scattering. For photon scattering, the deflection angle was determined by the differential scattering cross sections. An angular response function was developed and used to model the accepted angles for photon interaction with the crystal, and a detector scattering kernel was used for modeling the photon scattering in the detector. Predefined energy and spatial resolution kernels for the crystal were used. The MC code was implemented in the OSEM reconstruction of clinical and phantom 177Lu SPECT/CT images. The Jaszczak image quality phantom was used to evaluate the performance of the MC reconstruction in comparison with attenuated corrected (AC) OSEM reconstructions and attenuated corrected OSEM reconstructions with resolution recovery corrections (RRC). RESULT: The performance of the MC code was 3200 million photons/s. The required number of photons emitted per voxel to obtain a sufficiently low noise level in the simulated image was 200 for a 1283 voxel matrix. With this number of emitted photons/voxel, the MC-based OSEM reconstruction with ten subsets was performed within 20 s/iteration. The images converged after around six iterations. Therefore, the reconstruction time was around 3 min. The activity recovery for the spheres in the Jaszczak phantom was clearly improved with MC-based OSEM reconstruction, e.g., the activity recovery was 88% for the largest sphere, while it was 66% for AC-OSEM and 79% for RRC-OSEM. CONCLUSION: The GPU-based MC code generated an MC-based SPECT/CT reconstruction within a few minutes, and reconstructed patient images of 177Lu-DOTATATE treatments revealed clearly improved resolution and contrast.

Reporting individual surgeon outcomes does not lead to risk aversion in abdominal aortic aneurysm surgery.

INTRODUCTION Reporting surgeons' outcomes has recently been introduced in the UK. This has the potential to result in surgeons becoming risk averse. The aim of this study was to investigate whether reporting outcomes for abdominal aortic aneurysm (AAA) surgery impacts on the number and risk profile (level of fitness) of patients offered elective treatment. METHODS Publically available National Vascular Registry data were used to compare the number of AAAs treated in those centres across the UK that reported outcomes for the periods 2008-2012, 2009-2013 and 2010-2014. Furthermore, the number and characteristics of patients referred for consideration of elective AAA repair at a single tertiary unit were analysed yearly between 2010 and 2014. Clinic, casualty and theatre event codes were searched to obtain all AAAs treated. The results of cardiopulmonary exercise testing (CPET) were assessed. RESULTS For the 85 centres that reported outcomes in all three five-year periods, the median number of AAAs treated per unit increased between the periods 2008-2012 and 2010-2014 from 192 to 214 per year (p=0.006). In the single centre cohort study, the proportion of patients offered elective AAA repair increased from 74% in 2009-2010 to 81% in 2013-2014, with a maximum of 84% in 2012-2013. The age, aneurysm size and CPET results (anaerobic threshold levels) for those eventually offered elective treatment did not differ significantly between 2010 and 2014. CONCLUSIONS The results do not support the assumption that reporting individual surgeon outcomes is associated with a risk averse strategy regarding patient selection in aneurysm surgery at present.

Patients with Small Abdominal Aortic Aneurysm are at Significant Risk of Cardiovascular Events and this Risk is not Addressed Sufficiently.

BACKGROUND: Patients with abdominal aortic aneurysm (AAA) are at significant risk of cardiovascular (CV) events. Recent implementation of AAA-screening means thousands of patients are now diagnosed with small-AAA; however, CV risk factors are not always addressed. This study aimed at assessing and quantifying the CV characteristics of patients with small AAA following the introduction of screening programmes. METHODS: CV profiles of 384 men with a small AAA (<55 mm diameter) were assessed through the United Kingdom Aneurysm Growth Study (UKAGS), a nationwide prospective cohort study of men with small AAA. A prospective local cohort of an additional 142 patients with small AAA with available blood pressure (BP) and lipid profiles was also included and followed-up for 1 year. RESULTS: In the UKAGS population, 54% were current and 30% ex-smokers; 58% were hypertensive and 54% hypercholesterolaemic. In the local group, 54% were current and 40% were ex-smokers, and 94% were hypertensive. Patients were not more likely to receive CV medication after entering AAA surveillance in either group. All local patients were clustered "high-risk" for future CV events based on the Framingham score (mean 21.8%, 95% CI 20.0-23.6), JBS-2 (16.3%, 14.7-17.9) and ASSIGN (25.2%, 22.7-27.7). No change was seen in systolic BP levels between baseline and 1 year (140.9 mmHg vs. 142.5 mmHg, p=.435). A rise was seen in cholesterol (4.0 mmol-4.2 mmol, p<.0001) values at 1 year. CONCLUSIONS: This study suggests that patients with small AAA are at significant risk for developing CV events and this is not currently addressed, which is evident by the "high-risk" CV risk profiles of these patients despite being in AAA surveillance. Design and implementation of a CV risk reduction programme tailored for this population is necessary.

A STUDY OF THE IMAGE QUALITY OF COMPUTED TOMOGRAPHY ADAPTIVE STATISTICAL ITERATIVE RECONSTRUCTED BRAIN IMAGES USING SUBJECTIVE AND OBJECTIVE METHODS.

The recent reintroduction of iterative reconstruction in computed tomography has facilitated the realisation of major dose saving. The aim of this article was to investigate the possibility of achieving further savings at a site with well-established Adaptive Statistical iterative Reconstruction (ASiR™) (GE Healthcare) brain protocols. An adult patient study was conducted with observers making visual grading assessments using image quality criteria, which were compared with the frequency domain metrics, noise power spectrum and modulation transfer function. Subjective image quality equivalency was found in the 40-70% ASiR™ range, leading to the proposal of ranges for the objective metrics defining acceptable image quality. Based on the findings of both the patient-based and objective studies of the ASiR™/tube-current combinations tested, 60%/305 mA was found to fall within all, but one, of these ranges. Therefore, it is recommended that an ASiR™ level of 60%, with a noise index of 12.20, is a viable alternative to the currently used protocol featuring a 40% ASiR™ level and a noise index of 11.20, potentially representing a 16% dose saving.

A novel statistical analysis method to improve the detection of hepatic foci of (111)In-octreotide in SPECT/CT imaging.

BACKGROUND: Low uptake ratios, high noise, poor resolution, and low contrast all combine to make the detection of neuroendocrine liver tumours by (111)In-octreotide single photon emission tomography (SPECT) imaging a challenge. The aim of this study was to develop a segmentation analysis method that could improve the accuracy of hepatic neuroendocrine tumour detection. METHODS: Our novel segmentation was benchmarked by a retrospective analysis of patients categorized as either (111)In-octreotide positive ((111)In-octreotide(+)) or (111)In-octreotide negative ((111)In-octreotide(-)) for liver tumours. Following a 3-year follow-up period, involving multiple imaging modalities, we further segregated (111)In-octreotide-negative patients into two groups: one with no confirmed liver tumours ((111)In-octreotide(-)/radtech(-)) and the other, now diagnosed with liver tumours ((111)In-octreotide(-)/radtech(+)). We retrospectively applied our segmentation analysis to see if it could have detected these previously missed tumours using (111)In-octreotide. Our methodology subdivided the liver and determined normalized numbers of uptake foci (nNUF), at various threshold values, using a connected-component labelling algorithm. Plots of nNUF against the threshold index (ThI) were generated. ThI was defined as follows: ThI = (c max - c thr)/c max, where c max is the maximal threshold value for obtaining at least one, two voxel sized, uptake focus; c thr is the voxel threshold value. The maximal divergence between the nNUF values for (111)In-octreotide(-)/radtech(-), and (111)In-octreotide(+) livers, was used as the optimal nNUF value for tumour detection. We also corrected for any influence of the mean activity concentration on ThI. The nNUF versus ThI method (nNUFTI) was then used to reanalyze the (111)In-octreotide(-)/radtech(-) and (111)In-octreotide(-)/radtech(+) groups. RESULTS: Of a total of 53 (111)In-octreotide(-) patients, 40 were categorized as (111)In-octreotide(-)/radtech(-) and 13 as (111)In-octreotide(-)/radtech(+) group. Optimal separation of the nNUF values for (111)In-octreotide(-)/radtech(-) and (111)In-octreotide(+) groups was defined at the nNUF value of 0.25, to the right of the bell shaped nNUFTI curve. ThIs at this nNUF value were dependent on the mean activity concentration and therefore normalized to generate nThI; a significant difference in nThI values was found between the (111)In-octreotide(-)/radtech(-) and the (111)In-octreotide(-)/radtech(+) groups (P < 0.01). As a result, four of the 13 (111)In-octreotide(-)/radtech(+) livers were redesigned as (111)In-octreotide(+). CONCLUSIONS: The nNUFTI method has the potential to improve the diagnosis of liver tumours using (111)In-octreotide.

Evaluation of a new system for chest tomosynthesis: aspects of image quality of different protocols determined using an anthropomorphic phantom.

OBJECTIVE: To compare the image quality obtained with the different protocols in a new chest digital tomosynthesis (DTS) system. METHODS: A chest phantom was imaged with chest X-ray equipment with DTS. 10 protocols were used, and for each protocol, nine acquisitions were performed. Four observers visually rated the quality of the reconstructed section images according to pre-defined quality criteria in four different classes. The data were analysed with visual grading characteristics (VGC) analysis, using the vendor-recommended protocol [12-s acquisition time, source-to-image distance (SID) 180 cm] as reference, and the area under the VGC curve (AUCVGC) was determined for each protocol and class of criteria. RESULTS: Protocols with a smaller swing angle resulted in a lower image quality for the classes of criteria "disturbance" and "homogeneity in nodule" but a higher image quality for the class "structure". The class "demarcation" showed little dependency on the swing angle. All protocols but one (6.3 s, SID 130 cm) obtained an AUCVGC significantly <0.5 (indicating lower quality than reference) for at least one class of criteria. CONCLUSION: The study indicates that the DTS protocol with 6.3 s yields image quality similar to that obtained with the vendor-recommended protocol (12 s) but with the clinically important advantage for patients with respiratory impairment of a shorter acquisition time. ADVANCES IN KNOWLEDGE: The study demonstrates that the image quality may be strongly affected by the choice of protocol and that the vendor-recommended protocol may not be optimal.

Systematic review of cardiovascular disease and cardiovascular death in patients with a small abdominal aortic aneurysm.

BACKGROUND: Screening for abdominal aortic aneurysm (AAA) has reduced the rate of AAA rupture. However, cardiovascular disease is still a major cause of death in men with an AAA. The aim of this study was to assess cardiovascular risk in patients with a small AAA. METHODS: Standard PRISMA guidelines were followed. Analysis was performed of studies reporting cardiovascular outcomes in patients with a small AAA (30-54 mm). Weighted metaregression was performed for cardiovascular death in patients with a small AAA, and the prevalence of cardiovascular disease was reviewed. RESULTS: Twenty-one articles were identified describing patients with an AAA, and the prevalence of, and death from, cardiovascular disease. Ten of these reported cardiovascular death rates in patients with a small AAA. Some 2323 patients with a small AAA were identified; 335 cardiovascular deaths occurred, of which 37 were due to AAA rupture. Metaregression demonstrated that the risk of cardiovascular death was 3·0 (95 per cent c.i. 1·7 to 4·3) per cent per year in patients with a small AAA (R(2) = 0·902, P < 0·001). The prevalence of ischaemic heart disease (44·9 per cent), myocardial infarction (26·8 per cent), heart failure (4·4 per cent) and stroke (14·0 per cent) was also high in these patients. CONCLUSION: The risk of cardiovascular death in patients with a small AAA is high and increases by approximately 3 per cent each year after diagnosis. Patients with a small AAA have a high prevalence of cardiovascular disease. Patients a small AAA should be considered for lifestyle modifications and secondary cardiovascular protection.

Optimisation of occupational radiological protection in image-guided interventions: potential impact of dose rate measurements.

The optimisation of occupational radiological protection is challenging and a variety of factors have to be considered. Physicians performing image-guided interventions are working in an environment with one of the highest radiation risk levels in healthcare. Appropriate knowledge about the radiation environment is a prerequisite for conducting the optimisation process. Information about the dose rate variation during the interventions could provide valuable input to this process. The overall purpose of this study was to explore the prerequisite and feasibility to measure dose rate in scattered radiation and to assess the usefulness of such data in the optimisation process.Using an active dosimeter system, the dose rate in the unshielded scattered radiation field was measured in a fixed point close to the patient undergoing an image-guided intervention. The measurements were performed with a time resolution of one second and the dose rate data was continuously timed in a data log. In two treatment rooms, data was collected during a 6 month time period, resulting in data from 380 image-guided interventions and vascular treatments in the abdomen, arms and legs. These procedures were categorised into eight types according to the purpose of the treatment and the anatomical region involved.The dose rate varied substantially between treatment types, both regarding the levels and the distribution during the procedure. The maximum dose rate for different types of interventions varied typically between 5 and 100 mSv h(-1), but substantially higher and lower dose rates were also registered. The average dose rate during a complete procedure was however substantially lower and varied typically between 0.05 and 1 mSv h(-1). An analysis of the distribution disclosed that for a large part of the treatment types, the major amount of the total accumulated dose for a procedure was delivered in less than 10% of the exposure time and in less than 1% of the total procedure time.The present study shows that systematic dose rate measurements are feasible. Such measurements can be used to give a general indication of the exposure level to the staff and could serve as a first risk assessment tool when introducing new treatment types or x-ray equipment in the clinic. For example, it could provide an indication for when detailed eye dose measurements are needed. It also gives input to risk management considerations and the development of efficient routines for other radiological protection measures.

A retrospective study: Factors associated with the risk of abdominal aortic aneurysm rupture.

INTRODUCTION: Literature regarding pharmacological manipulation of aneurysm development and progression is abundant; however studies looking at preventing rupture are sparse. Moreover, best medical therapy is ill-instituted, and continued in this high-risk cohort. This paper aims to identify factors which affect the risk of AAA-rupture. MATERIALS & METHODS: A retrospective review of patients undergoing non-screen detected AAA-repair at a single tertiary-referral centre was performed. Age, cardiovascular history, medication use and the nature of surgical repair (elective or emergency) were converted to binary characteristics and a binomial logistic regression performed. RESULTS: We included 315 admissions for ruptured AAA, and 668 referrals for elective repair of large aneurysms (n=983). Multifactorial analysis showed that the cohort which was prescribed statins experienced fewer ruptured AAA ([OR] 0.50, [95% CI] 0.32-0.77). Factors associated with increased risk of rupture include female gender (2.49, 1.63-3.80), history of hypertension (3.5, 1.6-3.8) or renal failure (8.08, 4.15-15.4), age over 80 (2.77, 1.79-4.27) and current smoking (1.80, 1.09-2.96). DISCUSSION AND CONCLUSIONS: This is the largest study, interrogating individual patient data, to suggest an association between statins and prevention of large AAA-rupture. As patients with AAA are at high risk of cardiovascular events, and statins may decrease the risk of the devastating consequence of the condition, healthcare teams should maintain pharmaco-vigilance in instituting and continuing best medical therapy, including a statin.

Evaluation of the impact of a system for real-time visualisation of occupational radiation dose rate during fluoroscopically guided procedures.

Optimisation of radiological protection for operators working with fluoroscopically guided procedures has to be performed during the procedure, under varying and difficult conditions. The aim of the present study was to evaluate the impact of a system for real-time visualisation of radiation dose rate on optimisation of occupational radiological protection in fluoroscopically guided procedures. Individual radiation dose measurements, using a system for real-time visualisation, were performed in a cardiology laboratory for three cardiologists and ten assisting nurses. Radiation doses collected when the radiation dose rates were not displayed to the staff were compared to radiation doses collected when the radiation dose rates were displayed. When the radiation dose rates were displayed to the staff, one cardiologist and the assisting nurses (as a group) significantly reduced their personal radiation doses. The median radiation dose (Hp(10)) per procedure decreased from 68 to 28 µSv (p = 0.003) for this cardiologist and from 4.3 to 2.5 µSv (p = 0.001) for the assisting nurses. The results of the present study indicate that a system for real-time visualisation of radiation dose rate may have a positive impact on optimisation of occupational radiological protection. In particular, this may affect the behaviour of staff members practising inadequate personal radiological protection.

In-plane visibility of lesions using breast tomosynthesis and digital mammography.

PURPOSE: The purpose of this work was to evaluate the visibility of simulated lesions in 2D digita mammography (DM) and breast tomosynthesis (BT) images of patients. METHODS: Images of the same women were acquired on both a DM system (Mammomat Novation, Siemens Healthcare, Erlangen, Germany) and a BT prototype system adapted from the same type of DM system. Using the geometrical properties of the two systems, simulated lesions were projected and added to each DM image as well as to each BT projection image prior to 3D reconstruction. The same beam quality and approximately the same total absorbed dose to the glandular tissue were used for each breast image acquisition on the two systems. A series of four-alternative forced choice human observer experiments was conducted for each of five simulated lesion diameters: 0.2, 1, 3, 8, and 25 mm. An additional experiment was conducted for the 0.2 mm lesion in BT only at twice the dose level (BT2x). Threshold signal was defined as the lesion signal intensity required for a detectability index (d') of 2.5. Four medical physicists participated in all experiments. One experiment, consisting of 60 cases, was conducted per test condition (i.e., lesion size and signal combination). RESULTS: For the smallest lesions (0.2 mm), the threshold signal for DM was 21% lower than for BT at equivalent dose levels, and BT2x was 26% lower than DM. For the lesions larger than 1 mm, the threshold signal increased linearly (in log space) with the lesion diameter for both DM and BT, with DM requiring around twice the signal as BT. The difference in the threshold signal between BT and DM at each lesion size was statistically significant, except for the 0.2 mm lesion between BT2x and DM. CONCLUSIONS: The results of this study indicate that low-signal lesions larger than 1.0 mm may be more visible in BT compared to DM, whereas 0.2 mm lesions may be better visualized with DM compared to BT, when compared at equal dose.