Selecting the number and values of the CPWI steering angles and the effect of that on imaging quality

Compounded Plane-Wave Imaging (CPWI) has the ability to provide ultrafast imaging for many applications like colour flow imaging, microbubble imaging and elastography. The compounding operation improves the imaging quality at the expense of reducing the frame rate. Due to the importance of frame rate in ultrafast imaging, selecting the number and value of the compounded angles is a critical step to achieve the best possible imaging quality using the minimum number of angles whilst preserving the frame rate. This paper produces a new method for selecting the angular range and the number of angles in CPWI depending on the characteristics of the transducer and medium using Field II program. Experiments were performed on a wire phantom to show the efficiency of the produced method. The results show a comparative imaging quality of CPWI at the selected parameters when compared with linear imaging

Two-way Quality Assessment Approach for Tumour Detection using Free-hand Strain Imaging

A novel two-way image quality assessment method is proposed for free-hand strain imaging. In elasticity imaging, tissue with different stiffness exhibit varying contrast in the strain images and detectability of a lesion is measured using elastographic contrast-to-noise ratio (CNRe). Representing quality of strain images quantitatively is vital for improving imaging techniques and also for clinical diagnosis. It avoids the subjective approach of interpreting strain images. Conventionally, contrast between stiff lesion and surrounding soft tissue is measured using contrast-to-noise ratio and strain image with the highest CNRe amplitude is considered an optimal strain image. However experimental results have suggested that merely CNRe metric is often misleading and does not always represent the true elastic modulus contrast as the correlation coefficient falls below an acceptable levels and accuracy is compromised. Therefore in this study, the objective is to propose a comprehensive strain image quality assessment method which is reliable for clinical examinations and research

In vitro characterisation of low-cost synthetic meshes intended for hernia repair in the UK

Purpose: Low-cost meshes (LCM) were repurposed for the repair of hernias in the developing world. In vivo studies have shown LCM to have comparable results to commercial meshes (CM) at a fraction of the cost. However, little has been done to characterise the mechanical and biocompatible properties of LCM, preventing its clinical use in the UK. The objectives of the research are to assess mechanical and ultrastructural properties of two UK-sourced low-cost meshes (LCM) and the characterisation of the LCMs in vitro biocompatibility. Methods: Mechanical properties of the two LCM were measured through uniaxial tensile test and ultrastructure was evaluated with Scanning Electron Microscopy. LIVE/DEAD Viability/Cytotoxicity Assay kit and alamarBlue were used to assess cellular viability and proliferation, respectively. Images were acquired with a fluorescence microscope and analysed using ImageJ (NIH, USA). Results: LCM1 and LCM2 were both multifilament meshes, with the first having smaller pores than the latter. LCM1 exhibited significantly higher tensile strength (p < 0.05) than LCM2 but significantly lower extensibility (p < 0.0001), while Young’s Modulus of the two samples was not significantly different. No significant difference was found in the cellular viability and morphology cultured in LCM1 and LCM2 conditioned media. Metabolic assay and fluorescence imaging showed cellular attachment and proliferation on both LCMs over 14 days. Conclusion: The characterisation of the two UK-sourced LCMs showed in vitro biocompatibility and mechanical and ultrastructural properties comparable to the equivalent CM. This in vitro data represents a step forward for the feasibility of adopting LCM for surgical repair of hernias in the UK.

Parental [correction of Perinatal] consanguinity: a risk factor for developmental delay in Pakistani children

Objective: To investigate the association of parental consanguinity and delayed development in terms of gross motor, fine motor, speech and social aspects in their children.Methods: One hundred and seventy seven children (age 15 days--72 months) were evaluated for their developmental status utilizing the Denver Developmental Screening Test (DDST). An unmatched case-control study design was used. Case group consisted of 94 children and control group 83 children. Odds ratios were calculated for parental consanguinity and delay in gross and fine motor, speech and social development in their children, for cases and controls, utilizing Binary Multiple Logistic Regression Analysis. Acquired delay was excluded through detailed birth history in both cases and control group respectively.Results: Univariate analysis showed high significant Odds ratios for all areas of developmental delay (viz. gross and fine motor, speech and social development), between cases and controls (p \u3c .001). At the multivariate analysis level however, our results showed no increased risk of parental consanguinity on delayed gross and fine motor, speech and social development in their children.Conclusion: Our results show no increased risk of parental consanguinity on delayed gross and fine motor, speech or social development (as measured by the DDST), in their children

Improved shear wave-front reconstruction method by aligning imaging beam angles with shear-wave polarization: Applied for shear compounding application

In shear compounding, shear waves are generated at various angles and individual elasticity maps are averaged to reduce noise and improve accuracy. The steered shear waves tilt the tissue motion direction therefore conventional plane wave tracking is not capable of capturing true shear wave amplitude and direction. The proposed method aligns the tracking beams with the shear wave angles, enables beam-axis in the direction of tissue motion to estimate true shear wave motion vector. In this experimental work, shear waves are produced at five different angles and motion is captured using proposed and conventional method. All the experiments are conducted using inclusion-based elasticity phantom. In the results, the displacement maps show that proposed method accurately captured the steered push-beam wave-fronts while conventional method produced push-beam direction artefacts. In the final compounded elasticity maps, the proposed method slightly improved background-to-inclusion elasticity ratio, CNR by 2 dB, and produced inclusion boundary shape sharper than the conventional tracking

Contact structures in the poultry industry in Great Britain: Exploring transmission routes for a potential avian influenza virus epidemic

Background: The commercial poultry industry in United Kingdom (UK) is worth an estimated £3.4 billion at retail value, producing over 174 million birds for consumption per year. An epidemic of any poultry disease with high mortality or which is zoonotic, such as avian influenza virus (AIV), would result in the culling of significant numbers of birds, as seen in the Netherlands in 2003 and Italy in 2000. Such an epidemic would cost the UK government millions of pounds in compensation costs, with further economic losses through reduction of international and UK consumption of British poultry. In order to better inform policy advisers and makers on the potential for a large epidemic in GB, we investigate the role that interactions amongst premises within the British commercial poultry industry could play in promoting an AIV epidemic, given an introduction of the virus in a specific part of poultry industry in Great Britain (GB). Results: Poultry premises using multiple slaughterhouses lead to a large number of premises being potentially connected, with the resultant potential for large and sometimes widespread epidemics. Catching companies can also potentially link a large proportion of the poultry population. Critical to this is the maximum distance traveled by catching companies between premises and whether or not between-species transmission could occur within individual premises. Premises closely linked by proximity may result in connections being formed between different species and or sectors within the industry. Conclusion: Even quite well-contained epidemics have the potential for geographically widespread dissemination, potentially resulting in severe logistical problems for epidemic control, and with economic impact on a large part of the country. Premises sending birds to multiple slaughterhouses or housing multiple species may act as a bridge between otherwise separate sectors of the industry, resulting in the potential for large epidemics. Investment into further data collection and analyses on the importance of industry structure as a determinant for spread of AIV would enable us to use the results from this study to contribute to policy on disease control

Improved shear wave-front reconstruction method by aligning imaging beam angles with shear-wave polarization: Applied for shear compounding application

In shear compounding, shear waves are generated at various angles and individual elasticity maps are averaged to reduce noise and improve accuracy. The steered shear waves tilt the tissue motion direction therefore conventional plane wave tracking is not capable of capturing true shear wave amplitude and direction. The proposed method aligns the tracking beams with the shear wave angles, enables beam-axis in the direction of tissue motion to estimate true shear wave motion vector. In this experimental work, shear waves are produced at five different angles and motion is captured using proposed and conventional method. All the experiments are conducted using inclusion-based elasticity phantom. In the results, the displacement maps show that proposed method accurately captured the steered push-beam wave-fronts while conventional method produced push-beam direction artefacts. In the final compounded elasticity maps, the proposed method slightly improved background-to-inclusion elasticity ratio, CNR by 2 dB, and produced inclusion boundary shape sharper than the conventional tracking. © 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works

Assessing the coherence in biological and environmental drivers of young sea bass abundance across important estuarine nursery areas of the northern European sea bass stock

Year class strength is an important determinant of fish population size, but the drivers are often unknown. The northern stock of European sea bass (Dicentrarchus labrax) is an important target species for both commercial and recreational fisheries. Scientific assessments showed a rapid decline in spawning stock biomass from 2010-18 attributed to a combination of fishing mortality and poor year class strength. Recruitment to the adult stock is linked to the abundance and temporal dynamics of young bass in estuarine nursery areas, but little is known about the relative importance of environmental and biological drivers on the survival of these young life stages. In this study, we use Generalised Linear Models to attempt to identify important local environmental (sea surface temperature and river flow) and biological (chlorophyll-a concentration and predator abundance) drivers of young sea bass abundance. We focus on seven British and Irish estuarine areas that are important to the northern stock of European sea bass. In four English estuarine areas there were good model fits to the abundance of young sea bass, but predictors differed amongst these suggesting that drivers of abundance may differ among individual nursery areas. This was further demonstrated by poor fits of models generated for English estuaries to interannual patterns of abundance in the Irish nursery areas tested. The differences found in the most important abundance drivers amongst areas highlight the complex and differing dynamics between estuaries. If the number of young bass that eventually join the adult stock is dependent on survivors from a diverse set of unique nursery area conditions, then endeavours to incorporate this knowledge into fisheries management should be further explored

Thermally and mechanically robust self-healing supramolecular polyurethanes featuring aliphatic amide end caps

A series of supramolecular polyurethanes (SPUs) were designed and synthesised with synergetic multifunctional hydrogen bonding aliphatic amide end-caps. Hydrogen bonding between the urethane, urea, and amide motifs in the polymers afford strong dynamic association between polymer chains in the solid state. Phase separation of the apolar and polar components of the polyurethanes also serves to reinforce their thermal and mechanical properties. The supramolecular polyurethane with bisamide-morpholine end caps associates via multiple hydrogen bonds and exhibits enhanced tensile and thermal properties when compared to the other materials. Variable-temperature infrared spectroscopy (VT-IR) and atomic force microscopy (AFM), were carried out to study the phase morphology of the polymers and revealed a correlation between increased phase separation and the introduction of amide motifs in the end-caps. These SPUs also exhibit excellent healing abilities, requiring temperatures > 200 °C to recover their physical properties