Validated novel software to measure the conspicuity index of lesions in DICOM images

Description of purpose A novel software programme and associated Excel spreadsheet has been developed to provide an objective measure of the expected visual detectability of focal abnormalities within DICOM images. Methodology ROIs are drawn around the abnormality, the software then fits the lesion using a least squares method to recognise the edges of the lesion based on the full width half maximum. 180 line profiles are then plotted around the lesion, giving 360 edge profiles. The co-ordinates show in Figure 1 are captured, as well the standard deviation of the pixel values within the background and lesion (representing anatomical noise and lesion noise respectively). An Excel spreadsheet has been developed to allow variables to be calculated, including SNR and CNR. A conspicuity index has also been developed: Results The software has been validated using the GAMMEX ACR CT accreditation phantom, varying mA, kVp and slice thickness (ST) and the results have been found to give a linear response: Conclusion A novel software programme has been validated to allow calculation of many physical properties of lesions. Additionally, a new measure of conspicuity index has been developed for focal lesions. The analysis could be further developed to incorporate reader decision-analysis data and eye-tracking data allowing correlations between physical and perception measures to be made beyond basic CNR calculations. It could also be used as a tool to distinguish between perceptual and cognitive error. Further refinements could lead to measures of the detectability of more diffuse disease features

THERACOM: a systematic review of the evidence base for interventions to improve Therapeutic Communications between black and minority ethnic populations and staff in specialist mental health services.

PMCID: PMC3599664This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.BACKGROUND: Black and Minority Ethnic (BME) groups in receipt of specialist mental health care have reported higher rates of detention under the mental health act, less use of psychological therapies, and more dissatisfaction. Although many explanations have been put forward to explain this, a failure of therapeutic communications may explain poorer satisfaction, disengagement from services and ethnic variations in access to less coercive care. Interventions that improve therapeutic communications may offer new approaches to tackle ethnic inequalities in experiences and outcomes. METHODS: The THERACOM project is an HTA-funded evidence synthesis review of interventions to improve therapeutic communications between black and minority ethnic patients in contact with specialist mental health services and staff providing those services. This article sets out the protocol methods for a necessarily broad review topic, including appropriate search strategies, dilemmas for classifying different types of therapeutic communications and expectations of the types of interventions to improve them. The review methods will accommodate unexpected types of study and interventions. The findings will be reported in 2013, including a synthesis of the quantitative and grey literature. DISCUSSION: A particular methodological challenge is to identify and rate the quality of many different study types, for example, randomised controlled trials, observational quantitative studies, qualitative studies and case studies, which comprise the full range of hierarchies of evidence. We discuss the preliminary methodological challenges and some solutions. (PROSPERO registration number: CRD42011001661)

Analysis of effective and organ dose estimation in CT when using mA modulation : a single scanner pilot study

Effective dose (ED) estimation in CT examinations can be obtained by combining dose length product (DLP) with published ED per DLP coefficients or performed using software. These methods do not account for tube current (mA) modulation which is influenced by patient size. Aim To compare different methods of organ and ED estimation to measured values when using mA modulation in CT chest, abdomen and pelvis examinations. Method Organ doses from CT of the chest, abdomen and pelvis were measured using digital dosimeters and a dosimetry phantom. ED was calculated. Six methods of estimating ED accounting for mA modulation were performed using ImPACT CTDosimetry and Dose Length Product to ED coefficients. Corrections for the phantom mass were applied resulting in 12 estimation methods. Estimated organ doses from ImPACT CTDosimtery were compared to measured values. Results Calculated EDs were; chest 12.35 mSv (±1.48 mSv); abdomen 8.74 mSv (±1.36 mSv) and pelvis 4.68 mSv (±0.75 mSv). There was over estimation in all three anatomical regions. Correcting for phantom mass improved agreement between measured and estimated ED. Organ doses showed overestimation of dose inside the scan range and underestimation outside the scan range. Conclusion Reasonable estimation of effective dose for CT of the chest and abdomen can be obtained using ImPACT CTDosimetry software or k-coefficients. Further work is required to improve the accuracy of ED estimation from CT of the pelvis. Accuracy of organ dose estimation has been shown to depend on the inclusion or exclusion of the organ from the scan range

Effects of increased compression with an ultrasound transducer on the conspicuity of breast lesions in a phantom

Ultrasound imaging of the breast is highly operator dependent. The amount of pressure applied with the transducer has a direct impact on the lesion visibility in breast ultrasound. The conspicuity index is a quantitative measure of lesion visibility, taking into account more parameters than standard measures that impact on lesion detection. This study assessed the conspicuity of lesions within a breast phantom using increased transducer compression in breast ultrasound. Methods : A phantom was constructed of gelatine to represent adipose tissue, steel wool for glandular/blood vessels and silicone spheres to represent lesions, this meant that the lesions were also compressible, but less than the surrounding tissue. The phantom was imaged under increasing transducer compression. The conspicuity index was measured using the Conspicuity Index Software. The distance between the transducer surface and lesion surface was measured as an indication of increased compression. Results : When moderate compression (17mm) was applied, the conspicuity index increased resulting in better visualisation of the silicone lesions. However, with increased compression the conspicuity index decreased. New work to be presented : The conspicuity index has never been demonstrated in ultrasound imaging before. This is preliminary phantom work to demonstrate the impact of increased transducer compression on quantitative lesion visibility assessment. Conclusion : The compression applied should be considered for optimum visualisation, as excessive pressure decreases conspicuity. However, further work needs to be conducted in order to consider other factors, such as density of the breast and lesion location, for a better understanding of the effect of compression on the visualisation of the lesion. A human study is planned

User interface design for mobile-based sexual health interventions for young people: Design recommendations from a qualitative study on an online Chlamydia clinical care pathway

Background: The increasing pervasiveness of mobile technologies has given potential to transform healthcare by facilitating clinical management using software applications. These technologies may provide valuable tools in sexual health care and potentially overcome existing practical and cultural barriers to routine testing for sexually transmitted infections. In order to inform the design of a mobile health application for STIs that supports self-testing and self-management by linking diagnosis with online care pathways, we aimed to identify the dimensions and range of preferences for user interface design features among young people. Methods: Nine focus group discussions were conducted (n=49) with two age-stratified samples (16 to 18 and 19 to 24 year olds) of young people from Further Education colleges and Higher Education establishments. Discussions explored young people's views with regard to: the software interface; the presentation of information; and the ordering of interaction steps. Discussions were audio recorded and transcribed verbatim. Interview transcripts were analysed using thematic analysis. Results: Four over-arching themes emerged: privacy and security; credibility; user journey support; and the task-technology-context fit. From these themes, 20 user interface design recommendations for mobile health applications are proposed. For participants, although privacy was a major concern, security was not perceived as a major potential barrier as participants were generally unaware of potential security threats and inherently trusted new technology. Customisation also emerged as a key design preference to increase attractiveness and acceptability. Conclusions: Considerable effort should be focused on designing healthcare applications from the patient's perspective to maximise acceptability. The design recommendations proposed in this paper provide a valuable point of reference for the health design community to inform development of mobile-based health interventions for the diagnosis and treatment of a number of other conditions for this target group, while stimulating conversation across multidisciplinary communities

A JAFROC study of nodule detection performance in CT images of a thorax acquired during PET/CT

Purpose Two types of CT images (modalities) are acquired in PET/CT: for attenuation correction (AC) and diagnosis. The purpose of the study was to compare nodule detection and localization performance between these two modalities. Methods CT images, using both modalities, of an anthropomorphic chest phantom containing zero or more simulated spherical nodules of 5, 8, 10 and 12 mm diameters and contrasts −800, −630 and 100 HU were acquired. An observer performance study using nine observers interpreting 45 normal (zero nodules) images and 47 abnormal images (1–3 nodules; average 1.26) was conducted using the free-response receiver operating characteristic (FROC) paradigm. Data were analysed using an R software package implemented jackknife alternative FROC (JAFROC) analysis. Both empirical areas under the equally weighted AFROC curve (wAFROC) and under the highest rating inferred ROC (HR-ROC) curve were used as figures of merit (FOM). To control the probability of Type I error test alpha was set at 0.05. Results Nodule detection as measured by either FOM was significantly better on the diagnostic quality images (2nd modality), irrespective of the method of analysis, [reader averaged inter-modality wAFROC FOM difference = −0.07 (−0.11,−0.04); reader averaged inter-modality HR-ROC FOM difference = −0.05 (−0.09, −0.01)]. Conclusion Nodule detection was statistically worse on images acquired for AC; suggesting that images acquired for AC should not be used to evaluate pulmonary pathology. Keywords PET/CT; Nodule detection; JAFRO

Does elevating image receptor increase breast receptor footprint and improve pressure balance?

There is no consensus in the literature regarding the image receptor (IR) position for the cradio-caudal projection in mammography. Some literature indicates the IR should be positioned to the infra mammary fold (IMF); other literature suggests the IR be raised 2 cm relative to the IMF. Using 16 female volunteers (32 breasts) and a pressure sensitive mat we investigated breast footprint and pressure balance with IR at IMF and IR 2 cm above the IMF. Breast area on IR and paddle and interface pressure between IR/breast and paddle/breast were recorded. A uniformity index (UI) gave a measure of pressure balance between IR/ breast and paddle/breast. IR breast footprint increases significantly by 13.81 cm2 (p < 0.02) when IR is raised by 2 cm. UI reduces from 0.4 to 0.00 (p ¼ 0.04) when positioned at IMF þ2 cm demonstrating an improved pressure balance. Practitioners should consider raising the IR by 2 cm relative to the IMF in clinical practice. Further work is suggested to investigate the effects of practitioner variability and breast asymmetry

Measuring trade-offs in nephrology : a systematic review of Discrete Choice Experiments and Conjoint Analysis studies

Background: Discrete Choice Experiment [DCE], Conjoint Analysis [CA], or Adaptive Conjoint Analysis [ACA] methods are increasingly applied to obtain patient, clinician or community preferences in nephrology. This study systematically reviews the above mentioned published choice studies providing an overview of the issues addressed, methods, and findings. Methods: Choice studies relating to nephrology were identified using electronic databases, including Medline, Embase, PsychINFO and Econlit from 1990 to 2015. For inclusion in the review, studies had to primarily relate to kidney disease and include results from statistical (econometric) analyses of respondents’ choice or preference. Studies meeting the inclusion criteria were assessed against a range of systematic review criteria, and methods and results summarised. Results: We identified 14 eligible studies from Europe, Australasia, North America, and Asia, reporting preferences for treatment or screening, patient experiences, quality of life, health outcomes and priority setting frameworks. Specific contexts included medical interventions in kidney transplantation and renal cell carcinoma, health policies for organ donation and allocation, dialysis modalities and end-of-life care; using a variety of statistical models. The characteristics of ‘time’ (i.e. transplant waiting time, dialysis hours, transport time) and ‘quality of life’ (pre and post-transplant, or pre and post-dialysis) consistently influenced patient and clinician preferences across the choice studies. Conclusions: Discrete choice experiments are increasingly used to obtain information about key preferences in kidney transplantation and dialysis. These study methods provide quantitative information about respondents’ trade-offs between conflicting clinical and policy objectives, and can establish how preferences vary among stakeholder groups

Comparison of breast and bowel cancer screening uptake patterns in a common cohort of South Asian women in England

Background: Inequalities in uptake of cancer screening by ethnic minority populations are well documented in a number of international studies. However, most studies to date have explored screening uptake for a single cancer only. This paper compares breast and bowel cancer screening uptake for a cohort of South Asian women invited to undertake both, and similarly investigates these women's breast cancer screening behaviour over a period of fifteen years. Methods: Screening data for rounds 1, 2 and 5 (1989-2004) of the NHS breast cancer screening programme and for round 1 of the NHS bowel screening pilot (2000-2002) were obtained for women aged 50-69 resident in the English bowel screening pilot site, Coventry and Warwickshire, who had been invited to undertake breast and bowel cancer screening in the period 2000-2002. Breast and bowel cancer screening uptake levels were calculated and compared using the chi-squared test. Results: 72,566 women were invited to breast and bowel cancer screening after exclusions. Of these, 3,539 were South Asian and 69,027 non-Asian; 18,730 had been invited to mammography over the previous fifteen years (rounds 1 to 5). South Asian women were significantly less likely to undertake both breast and bowel cancer screening; 29.9% (n = 1,057) compared to 59.4% (n = 40,969) for non-Asians (p < 0.001). Women in both groups who consistently chose to undertake breast cancer screening in rounds 1, 2 and 5 were more likely to complete round 1 bowel cancer screening. However, the likelihood of completion of bowel cancer screening was still significantly lower for South Asians; 49.5% vs. 82.3% for non-Asians, p < 0.001. South Asian women who undertook breast cancer screening in only one round were no more likely to complete bowel cancer screening than those who decided against breast cancer screening in all three rounds. In contrast, similar women in the non-Asian population had an increased likelihood of completing the new bowel cancer screening test. The likelihood of continued uptake of mammography after undertaking screening in round 1 differed between South Asian religio-linguistic groups. Noticeably, women in the Muslim population were less likely to continue to participate in mammography than those in other South Asian groups. Conclusions: Culturally appropriate targeted interventions are required to reduce observed disparities in cancer screening uptakes

An overview of measuring and modelling dose and risk from ionising radiation for medical exposures

PURPOSE: This paper gives an overview of the methods that are used to calculate dose and risk from exposure to ionizing radiation as a support to other papers in this special issue. BACKGROUND: The optimization of radiation dose is a legal requirement in medical exposures. This review paper aims to provide the reader with knowledge of dose by providing definitions and concepts of absorbed, effective and equivalent dose. Criticisms of the use of effective dose to infer the risk of an exposure to an individual will be discussed and an alternative approach considering the lifetime risks of cancer incidence will be considered. Prior to any dose or risk calculation, data concerning the dose absorbed by the patient needs to be collected. This paper will describe and discuss the main concepts and methods that can be utilised by a researcher in dose assessments. Concepts behind figures generated by imaging equipment such as dose-area-product, computed tomography dose index, dose length product and their use in effective dose calculations will be discussed. Processes, advantages and disadvantages in the simulation of exposures using the Monte Carlo method and direct measurement using digital dosimeters or thermoluminescent dosimeters will be considered. Beyond this special issue it is proposed that this paper could serve as a teaching or CPD tool for personnel working or studying medical imaging