3D printed kidney phantoms for an LED-based photoacoustic and ultrasound imaging system

Photoacoustic imaging is a powerful and increasingly popular technique for tissue diagnostics. Suitable tissue- equivalent phantoms are in high demand for validating photoacoustic imaging methods and for clinical training. In this work, we describe a method of directly 3D printing a photoacoustic tissue-equivalent phantom of a kidney based on Gel Wax, which is a mix of polymer and mineral oil. A kidney phantom that is compatible with photoacoustic scanning will enable clinicians to evaluate a portable LED-based photoacoustic and ultrasound imaging system as a means of locating tumors and other abnormalities. This represents a significant step towards clinical translation of the compact system. Training using realistic phantoms reduces the risks associated with clinical procedures. Complications during procedures can arise due to the specific structure of the kidney under investigation. Thus the ability to create a 3D printed phantom based on detailed anatomical images of a specific patient enables clinicians to train on a phantom with exactly the same structure as the kidney to be treated. Recently we developed a novel 3D printer based on gel wax. The device combines native gel wax with glass microspheres and titanium dioxide (TiO 2 ) particles to obtain a medium with tissue-like optical and acoustic properties. 3D models created using this printer can be given a range of values of optical absorption reduced scattering coefficients. The ability to 3D patient-specific phantoms at low cost has the potential to revolutionize the production and use of tissue-equivalent phantoms in future, and can be applied to a wide range of organs and imaging modalities

A review of a strategic roadmapping exercise to advance clinical translation of photoacoustic imaging: From current barriers to future adoption

Photoacoustic imaging (PAI), also referred to as optoacoustic imaging, has shown promise in early-stage clinical trials in a range of applications from inflammatory diseases to cancer. While the first PAI systems have recently received regulatory approvals, successful adoption of PAI technology into healthcare systems for clinical decision making must still overcome a range of barriers, from education and training to data acquisition and interpretation. The International Photoacoustic Standardisation Consortium (IPASC) undertook an community exercise in 2022 to identify and understand these barriers, then develop a roadmap of strategic plans to address them. Here, we outline the nature and scope of the barriers that were identified, along with short-, medium- and long-term community efforts required to overcome them, both within and beyond the IPASC group

Not Available

Not AvailableGlobally, marine fishery resources are under enor-mous pressure with the estimated fishing effortexceeding the optimum by a factor of three to four(Pauly et al., 2002). The economic losses due toexcess fishing effort have been estimated to be 50billion USD annually (World Bank, 2009). FAOestimated 52% of global fish stocks as fullyexploited, 28% overexploited or depleted, 20%moderately exploited, and only 1% showing signsof recovery as a result of the consequences offishing, since 1970 (FAO, 2009). Maharashtra witha coastline of 720 km is one of the leading states inIndia in marine fish production. Major fish landingcentres are New Ferry Wharf, Sassoon Dock andVersova, situated in Greater Mumbai (GRM) andthey account for nearly 60% of the state fish landings(Annam & Agustine, 2005; Mane & Sundaram,2011). Trawlers and purse seiners land largequantity of bycatch (60-65%) comprising juveniles,undersized fishes and inedible biota which isdiscarded at sea and mostly goes unreported. Themarine fishery in Maharashtra has been facing crisissince late nineties owing to overfishing, urbaniza-tion, domestic and industrial pollution and habitatdegradation (Deshmukh, 2013).Not Availabl

Properties, classification and agricultural potentials of the soils of lower Oshin river floodplains in Kwara State, Nigeria

A semi-detailed soil survey of the floodplains of lower Oshin River in Kwara State, Nigeria was carried out using rigid-grid survey method. Three soil units designated as OSH-1, OSH-2 and OSH-3 were identified on the basis of drainage, topography, soil texture and depth. The soil texture ranges from sandy clay loam in OSH-1 to sandy loam in OSH-2 and OSH-3 for the topsoil overlaying clay loam or sandy loam subsoil. The soil pH (H2O) was moderately to slightly acid with values ranged from 5.1-5.7 in OSH-1 and 5.9-6.9 in OSH-2 and OSH-3. The available P in all soil units decreased with soil depth and the values for the topsoil were 22, 40 and 10 mg kg-1 respectively for OSH-1, OSH-2 and OSH-3 and was rated high in OSH-1 and OSH-2, and medium in OSH-3. Also, organic C content for topsoil was 27.5, 35.5 and 28.0 g kg-1 for OSH-1, OSH-2 and OSH-3 and its distribution within the profiles was irregular except in OSH-1 where it decreased regularly with soil depth. The CEC value for the topsoil was between 19.14 and 21.99 cmol(+) kg-1 and all rated high. The soil units were classified as Typic Endoaquepts/ Fluvic Cambisols (Clayic), Aquic Ustifluvents/ Gleyic Fluvisols (Arenic) and Oxyaquic Ustifluvents/ Gleyic Fluvisols (Eutric) using USDA Soil Taxonomy and WRB systems respectively. With exception of drainage problems which can be overcome by provision of adequate drainage infrastructure, the soils of the lower River Oshin floodplain have great potential for rain-fed agriculture.Nigerian Journal of Technological Researc

Design and evaluation of a laboratory prototype system for 3D photoacoustic full breast tomography

Photoacoustic imaging can visualize vascularization-driven optical absorption contrast with great potential for breast cancer detection and diagnosis. State-of-the-art photoacoustic breast imaging systems are promising but are limited either by only a 2D imaging capability or by an insufficient imaging field-of-view (FOV). We present a laboratory prototype system designed for 3D photoacoustic full breast tomography, and comprehensively characterize it and evaluate its performance in imaging phantoms. The heart of the system is an ultrasound detector array specifically developed for breast imaging and optimized for high sensitivity. Each detector element has an acoustic lens to enlarge the acceptance angle of the large surface area detector elements to ensure a wide system FOV. We characterized the ultrasound detector array performance in terms of frequency response, directional sensitivity, minimum detectable pressure and inter-element electrical and mechanical cross-talk. Further we evaluated the system performance of the laboratory prototype imager using well-defined breast mimicking phantoms. The system possesses a 2 mm XY plane resolution and a 6 mm vertical resolution. A vasculature mimicking object was successfully visualized down to a depth of 40 mm in the breast phantom. Further, tumor mimicking spherical objects with 5 and 10 mm diameter at 20 mm and 40 mm depths are recovered, indicating high system sensitivity. The system has a 170 × 170 × 170 mm3 FOV, which is well suited for full breast imaging. Various recommendations are provided for performance improvement and to guide this laboratory prototype to a clinical version in future

Ultrasonic needle tracking with a fibre-optic ultrasound transmitter for guidance of minimally invasive fetal surgery

Ultrasound imaging is widely used for guiding minimally invasive procedures, including fetal surgery. Visualisation of medical devices such as medical needles is critically important and it remains challenging in many clinical contexts. During in-plane insertions, a needle can have poor visibility at steep insertion angles and at large insertion depths. During out-of-plane insertions, the needle tip can have a similar ultrasonic appearance to the needle shaft when it intersects with the ultrasound imaging plane. When the needle tip is not accurately identified, it can damage critical structures, with potentially severe consequences, including loss of pregnancy. In this paper, we present a tracking system to directly visualise the needle tip with an ultrasonic beacon. The waves transmitted by the beacon were received by an external ultrasound imaging probe. Pairs of co-registered images were acquired in rapid succession with this probe: a photoacoustic image obtained with the system in receive-only mode, and a conventional B-mode ultrasound image. The beacon comprised a custom elastomeric nanocomposite coating at the distal end of an optical fibre, which was positioned within the lumen of a commercial 22 gauge needle. Delivery of pulsed light to the coating resulted in the photoacoustic generation of ultrasonic waves. The measured tracking accuracies in water in the axial and lateral dimensions were 0.39±0.19 mm and 1.85±0.29 mm, respectively. To obtain a preliminary indication of the clinical potential of this ultrasonic needle tracking system, needle insertions were performed in an in vivo fetal sheep model. The results demonstrate that ultrasonic needle tracking with a fibre-optic transmitter is feasible in a clinically realistic fetal surgery environment, and that it could be useful to guide minimally invasive procedures by providing accurate visualisation of the medical device tip