SUSPENSION CRITERIA FOR IMAGE MONITORS AND VIEWING BOXES.

Image monitors and viewing boxes have a crucial role in the diagnostic process. Modern radiology uses different modalities to produce digital images which are to be viewed in different parts of the radiology department and throughout the hospital, sometimes simultaneously, via the Picture Archiving and Communications System (PACS). Therefore, the quality of the image monitors is of great importance. IPEM notes that inadequacies in the imaging viewing area may serve to negate the benefits of other efforts made to maintain quality and consistency. Suspension criteria for diagnostic image monitors and viewing boxes are presented in RP162. These criteria are mainly based on two documents, IPEM report 91, 'Recommended standards for the routine performance testing of diagnostic x-ray imaging systems' (2005) and AAPM on-line report no. 03, 'Assessment of display performance for medical imaging systems' (2005). The development of common European suspension levels for image monitors and viewing boxes will be a valuable tool in quality assurance

Nitrates and Left Ventricular Dysfunction

Use of beta-blockers and inhibitors of the renin angiotensin system (RAS) is established practice in the treatment of chronic heart failure (CHF). Clinical studies also suggest beneficial long-term effects of nitrates in CHF. In the Veterans Administration Heart Failure Trial (V-HeFT) I, the combined use of a nitrate and hydralazine reduced the mortality rate. However, it is not possible to determine the relative importance of nitrate therapy in that study. The main objective of this thesis was to study the long-term effects of nitrate therapy in patients with evidence of left ventricular (LV) dysfunction after acute myocardial infarction (AMI) already treated with standard heart failure (HF) therapy. Paper I. In a randomized, double-blind, placebo controlled trial, we evaluated the effects of a 60 mg dose of isosorbide-5-mononitrate (IS-5-MN) given daily to 47 patients with clinical or echocardiographic evidence of LV dysfunction after AMI. Forty-five patients received a placebo. No significant haemodynamic effects of IS-5-MN therapy were observed. We found that nitrate therapy resulted in lower plasma atrial natriuretic peptide (P ANP) levels and reduced the need for additional diuretics. Less LV dilatation was observed in patients with more severe LV dysfunction at baseline, indicating clinically beneficial effects, especially in patients with more reduced LV function after AMI. Paper II. The main finding of this study was that lipid peroxidation measured by plasma malondialdehyde (MDA) and 8-isoprostane were not increased in patients with LV dysfunction treated with standard HF therapy. No positive correlations to the markers of severity of HF were found. Long-term IS-5-MN therapy did not influence P-MDA concentrations. Results from many studies suggest that oxidative stress is increased in HF, but this may not be true for patients treated with beta-blockers and inhibitors of the RAS. Paper III. Chronic nitrate therapy did not significantly affect the neurohumoral status in patients with LV dysfunction after AMI, apart from a decrease in P-ANP. Some hormones were seen to be more closely associated with diastolic dysfunction/increased volume load, viz ANP and brain natriuretic peptide (BNP), while others were found to be more closely associated with systolic dysfunction, namely plasma renin activity (PRA), norepinephrine (NEPI) and aldosterone (Aldo). A temporal dissociation between these two groups of hormones occurred 1 year after the infarction: ANP and BNP decreased, while NEPI and Aldo showed slight increases. Paper IV. Isosorbide-5-mononitrate treatment and diastolic function were evaluated in patients with LV dysfunction after AMI. Chronic nitrate therapy did not significantly affect diastolic function evaluated by echocardiography. Changes in diastolic parameters during 1 year after AMI indicated improved diastolic function and/or reduced pre-load. Fewer factors indicating worse prognosis were demonstrated in patients with normal or slightly reduced LV ejection fraction (LVEF) 1 month after AMI, compared with patients with moderately or severely depressed LVEF

Child abuse - clinical investigation, management and nursing approach

The overall aim of this thesis is to describe how children suspected of being abused were taken care of in a large Children’s University hospital. Study I Aim: To evaluate clinical investigations for suspected child abuse in infants presenting to a Paediatric Emergency Department (ED) with certain primary complaints known to be associated with child abuse. Methods: All medical records of ED admissions that included at least one of the selected primary complaints and a record of a CT head scan having been performed were located in the hospital database. Forty seven medical records satisfied our inclusion criteria. Results: Eighty seven percent of the 47 children had a head injury as the initial diagnosis. Thirty eight percent of the children belonged to the age group 0-3 months. Of the children admitted to the ED due to a head injury, twenty two children (54%) had a history deemed to be suspicious for abuse while only one child had indeed been properly investigated for possible child abuse. Conclusion: Despite good reasons, only a small number of investigations of suspected child abuse were carried out in the Children’s hospital. The hospital staff had difficulties in properly recording whether there were any signs suspicious of child abuse. Study II Aim: To identify children diagnosed as victims of child abuse in a large Children’s University hospital during a four-year period, with focus on whether reports to social services were done. Methods: We studied retrospectively; all medical records of children assigned an ICD 10 code appropriate for child abuse. Results: We found 137 children diagnosed as victims of child abuse, out of which 42 were abused sexually while 95 where physically abused. According to the medical records, the medical staff reported only 55% of these cases to the social services. Conclusion: Efforts to improve knowledge of signs of child abuse is essential, as are intensified education concerning the laws requiring medical staff to report suspected child abuse and the proper procedures for such reporting. Study III Aim: The aim of this study is to identify children below 2 years of age who may have been physically abused by searching the medical records for reports of CT brain scans. Methods: The study group was identified using the computerized medical records database in the Children’s University Hospital. All CT head scan reports (n=1925) during a 8 year period were reviewed and we selected only those in which an intracranial haemorrhage was described. Results: The most common reason for admission to the ED was a fall from a low height (n=28). In 22/68 children (32%) the hospital staff filed a report to the social services. The neuroradiologist suggested child abuse as a possible explanation for the findings on the CT scan in 28 (41%) children. Of this subgroup 61 % (n=17) were investigated for child abuse and 15 (54%) of these children were reported to the social services. Conclusion: The neuroradiologist’s report is an indispensable part of the clinical investigation of possible child abuse. A mere description of the findings is not so useful. It is the opinion expressed by the neuroradiologist that the findings should lead to a further investigation of possible child abuse, that is important. Study IV Aim: The aim of this study was to identify nurse’s experiences in the clinical care of victims of child abuse. The objective was to assess how nurses could remain professional especially when the suspected perpetrator is a parent. Methods: Investigators used a qualitative design with a critical incident technique. Eleven nurses who cared for abused children and their parents in a tertiary care University children’s hospital were interviewed. Results: We highlighted three areas in the analysis of the interviews: Feelings of ambivalence, nurse’s professionalism and the nurse’s care strategies. The subjects expressed difficulties in maintaining a professional role in clinical encounters with the parents. The nurses experienced conflicts in their roles to deal with being both a police (a judicial function) and a nurse (a caring function). Conclusions: The nurses expressed that they had devised strategies to remain professional in the clinical encounter with abused children and their parents. To remain professional, education, counselling and experience was essential

Photoluminescence Properties and Fabrication of Red-Emitting LEDs based on Ca9Eu(VO4)(7) Phosphor

We study the photoluminescence properties of the red-emitting phosphor Ca9Eu(VO4)(7) and establish a strong red emission centered at 613 nm under excitation at 395 nm (near ultra violet light, near-UV light) due to the intra-configurational D-5(0) -> F-7(2) transition within the 4f(6) configuration of the Eu3+ ions. The intensity of the emitted light decreases with increasing temperature and at T = 470 K about 50% of the intensity of the emitted light at room temperature is lost. Five different red-LED prototypes were constructed by applying a mixture of Ca9Eu(VO4)(7) phosphor and silicone gel on the headers of near-UV LED chips. The prototypes showed a color output from violet for the lowest phosphor concentration (133 g phosphor /l silicone gel), reaching an almost pure red-light output for the highest phosphor concentration (670 g phosphor /l silicone gel). The luminous efficiency of optical radiation (LER) was found to decrease slightly with increasing applied current. For the highest phosphor concentration, the LER decreases from 238 lmW(-1) for 1 mA current supply to 235 lmW(-1) for 18 mA current supply. The external quantum efficiency decreased from 7.33% for the lowest phosphor containing LED prototype to 4.13% for the highest one. (C) The Author(s) 2019. Published by ECS

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

Weak thermal quenching of the luminescence in the Ca3Sc2Si3O12:Ce3+ garnet phosphor

We report results of the luminescence properties of the three garnet type phosphors Ce3+-doped Ca3Sc2Si3O12(CSSO:Ce3+), Sr3Y2Ge3O12(SYG:Ce3+) and Y3Al5O12(YAG:Ce3+), investigated using optical spectroscopy techniques and vacuum referred binding energy (VRBE) diagram analysis. By monitoring the temperature dependence of the luminescence decay time we establish an excellent, intrinsic, thermal stability of luminescence in CSSO:Ce3+, with a nearly constant decay time (≈60 ns) up to, at least, T = 860 K. In comparison, SYG:Ce3+and YAG:Ce3+exhibit a significant reduction of the luminescence decay time upon heating, starting at around T = 280 K and T = 550 K, respectively, suggesting a lower internal thermal stability of luminescence in these two garnet phosphors. These findings are supported by the energy separation between the Ce3+5d1level and the conduction band (CB) of the respective hosts, which are found at 1.36 eV (CSSO:Ce3+), 0.45 eV (SYG:Ce3+), and 1.17 eV (YAG:Ce3+), respectively, as predicted by their VRBE diagrams. The performance of CSSO:Ce3+was evaluated by applying the phosphor on a blue InGaN LED. The system shows a luminous efficacy of optical radiation of 243 lm W-1and a linear response with increasing applied voltage, suggesting it is a highly promising phosphor for future technological applications, particularly at high temperature operating environments

Assessment of perceptual distortion boundary through applying reversible watermarking to brain MR images

The digital medical workflow faces many circumstances in which the images can be manipulated during viewing, extracting and exchanging. Reversible and imperceptible watermarking approaches have the potential to enhance trust within the medical imaging pipeline through ensuring the authenticity and integrity of the images to confirm that the changes can be detected and tracked. This study concentrates on the imperceptibility issue. Unlike reversibility, for which an objective assessment can be easily made, imperceptibility is a factor of human cognition that needs to be evaluated within the human context. By defining a perceptual boundary of detecting the modification, this study enables the formation of objective guidelines for the method of data encoding and level of image/pixel modification that translates to a specific watermark magnitude. This study implements a relative Visual Grading Analysis (VGA) evaluation of 117 brain MR images (8 original and 109 watermarked), modified by varying techniques and magnitude of image/pixel modification to determine where this perceptual boundary exists and relate the point at which change becomes noticeable to the objective measures of the image fidelity evaluation. The outcomes of the visual assessment were linked to the images Peak Signal to Noise Ratio (PSNR) values, thereby identifying the visual degradation threshold. The results suggest that, for watermarking applications, if a watermark is applied to the 512x512 pixel (16 bpp grayscale) images used in the study, a subsequent assessment of PSNR=82dB or greater would mean that there would be no reason to suspect that the watermark would be visually detectable. Keywords: Medical imaging; DICOM; Reversible Watermarking; Imperceptibility; Image Quality; Visual Grading Analysis

The TOMMY trial: a comparison of TOMosynthesis with digital MammographY in the UK NHS Breast Screening Programme--a multicentre retrospective reading study comparing the diagnostic performance of digital breast tomosynthesis and digital mammography with digital mammography alone.

BACKGROUND: Digital breast tomosynthesis (DBT) is a three-dimensional mammography technique with the potential to improve accuracy by improving differentiation between malignant and non-malignant lesions. OBJECTIVES: The objectives of the study were to compare the diagnostic accuracy of DBT in conjunction with two-dimensional (2D) mammography or synthetic 2D mammography, against standard 2D mammography and to determine if DBT improves the accuracy of detection of different types of lesions. STUDY POPULATION: Women (aged 47-73 years) recalled for further assessment after routine breast screening and women (aged 40-49 years) with moderate/high of risk of developing breast cancer attending annual mammography screening were recruited after giving written informed consent. INTERVENTION: All participants underwent a two-view 2D mammography of both breasts and two-view DBT imaging. Image-processing software generated a synthetic 2D mammogram from the DBT data sets. RETROSPECTIVE READING STUDY: In an independent blinded retrospective study, readers reviewed (1) 2D or (2) 2D + DBT or (3) synthetic 2D + DBT images for each case without access to original screening mammograms or prior examinations. Sensitivities and specificities were calculated for each reading arm and by subgroup analyses. RESULTS: Data were available for 7060 subjects comprising 6020 (1158 cancers) assessment cases and 1040 (two cancers) family history screening cases. Overall sensitivity was 87% [95% confidence interval (CI) 85% to 89%] for 2D only, 89% (95% CI 87% to 91%) for 2D + DBT and 88% (95% CI 86% to 90%) for synthetic 2D + DBT. The difference in sensitivity between 2D and 2D + DBT was of borderline significance (p = 0.07) and for synthetic 2D + DBT there was no significant difference (p = 0.6). Specificity was 58% (95% CI 56% to 60%) for 2D, 69% (95% CI 67% to 71%) for 2D + DBT and 71% (95% CI 69% to 73%) for synthetic 2D + DBT. Specificity was significantly higher in both DBT reading arms for all subgroups of age, density and dominant radiological feature (p < 0.001 all cases). In all reading arms, specificity tended to be lower for microcalcifications and higher for distortion/asymmetry. Comparing 2D + DBT to 2D alone, sensitivity was significantly higher: 93% versus 86% (p < 0.001) for invasive tumours of size 11-20 mm. Similarly, for breast density 50% or more, sensitivities were 93% versus 86% (p = 0.03); for grade 2 invasive tumours, sensitivities were 91% versus 87% (p = 0.01); where the dominant radiological feature was a mass, sensitivities were 92% and 89% (p = 0.04) For synthetic 2D + DBT, there was significantly (p = 0.006) higher sensitivity than 2D alone in invasive cancers of size 11-20 mm, with a sensitivity of 91%. CONCLUSIONS: The specificity of DBT and 2D was better than 2D alone but there was only marginal improvement in sensitivity. The performance of synthetic 2D appeared to be comparable to standard 2D. If these results were observed with screening cases, DBT and 2D mammography could benefit to the screening programme by reducing the number of women recalled unnecessarily, especially if a synthetic 2D mammogram were used to minimise radiation exposure. Further research is required into the feasibility of implementing DBT in a screening setting, prognostic modelling on outcomes and mortality, and comparison of 2D and synthetic 2D for different lesion types. STUDY REGISTRATION: Current Controlled Trials ISRCTN73467396. FUNDING: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 19, No. 4. See the HTA programme website for further project information.This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 19, No. 4. See the HTA programme website for further project information.Gilbert FJ, Tucker L, Gillan MGC, Willsher P, Cooke J, Duncan KA, et al. The TOMMY trial: a comparison of TOMosynthesis with digital MammographY in the UK NHS Breast Screening Programme – a multicentre retrospective reading study comparing the diagnostic performance of digital breast tomosynthesis and digital mammography with digital mammography alone. Health Technol Assess 2015;19(4). © Queen’s Printer and Controller of HMSO 2015. This work was produced by Gilbert et al. under the terms of a commissioning contract issued by the Secretary of State for Health. This issue may be freely reproduced for the purposes of private research and study and extracts (or indeed, the full report) may be included in professional journals provided that suitable acknowledgement is made and the reproduction is not associated with any form of advertising. Applications for commercial reproduction should be addressed to: NIHR Journals Library, National Institute for Health Research, Evaluation, Trials and Studies Coordinating Centre, Alpha House, University of Southampton Science Park, Southampton SO16 7NS, UK