Tomographic Imaging: UK Collaborative Computational Projects

Computed Tomography (CT) is a powerful non-destructive evaluation (NDE) technique for producing 2-D cross-sections and 3-D images of an object from a series of 2D projections. Critical to the CT process is a pipeline of computer algorithms carrying out an interdependent sequence of tasks to extract the desired information from the raw data:

i) correction and calibration starting from initial image capture,
ii) reconstruction of a 3D image from these 2D projections,
iii) analysis and quantification of features in the 3D image, and
iv) 2D and 3D visualization and animation of the 3D image and extracted features.

While the techniques are rapidly growing in popularity, most users have fairly limited options when trying to recover the 3D image. They can either use black-box software tools provided by X-ray CT instrument manufacturers, or at best, write only fairly primitive computer programs to extract key features from the images. Large, mid-range and small CT facilities across the UK represent multi million pound investments of which the full return is not realised due to unmet method and software needs. Furthermore, best practices for data analysis and application of novel computational methods are yet not routinely shared across the community adding further barrier to reaching the full potential. There is a clear need improved software tools for extracting information from CT data, as well as for strengthening collaboration across and upskilling the CT community as a whole in terms of computational methods and software.

The CCPi aims to address both of these issues. Firstly, the CCPi seeks to provide fully open-source software covering the full tomographic imaging pipeline including pre-processing and calibration, a variety of reconstruction algorithms for different forms of challenging data, artefact reduction codes, and image analysis procedures. The collection of tools released under the name Core Imaging Library (CIL) caters for inexperienced users by easy-to-use standard algorithms, as well as giving expert users full flexibility to construct bespoke data processing pipelines. Secondly, the CCPi seeks to strengthen and grow the UK CT community through networking activities, staff exchanges, training and seminars. The activities will continue to connect a highly multi-disciplinary community of mathematicians, physicists, engineers, instrument scientists, researchers in the applied sciences (users) as well as industry and cultural heritage groups.

Economy

X-ray imaging is already well established in the security, non-destructive evaluation and health industries with 100,000 plus scanners worldwide. Increasingly CT is seen as a way of helping to develop new products, especially in the additive manufacturing area where identifying internal defects are critical, but also in many other areas where the relationship between manufacturing processes and part integrity is important, particularly for high value and safety critical components. We already have over 40 industrialists engaged in our CCP network including key UK based partners. Much of our funding is aimed at developing impact pathways to ensure that both the X-ray systems at facilities such as the large scale facilities, the newly established mid-scale National Research Facility and individual facilities are able to answer questions of key economic importance through the exploitation of new software and algorithms.

In the last phase industrial attendees have attended, presented and exhibited at our events to gain feedback, link up with users and in some cases to incorporate tools we have developed for their users.
With a work programme focused on workflows and industrial applications in CCPi's Phase III, industry will also have an increasing role on the Working Group to identify key issues from their perspective prior to developing the framework. As the CCP continues to develop it will broaden its remit into other tomographic applications (already incorporating code links with PET, MRI and Neutron Tomography) making this industrial focussed community larger and more important.

Knowledge

This CCPi will benefit; Diamond Light Source x-ray imaging users, ISIS Neutron and Muon spallation users, CLF laser-induced x-ray and those with access to laboratory and shared EPSRC strategic x-ray facilities.

People

The EPSRC Software Infrastructure Strategy 2018 identifies "people" as one its five key objectives. Three of the work program leads are early-career academics. The CCPi network will continue to upskill members within the community and has a strong record of developing young and mature researchers, both within the specific research groups and across the CCPi network. So far, in Phase II of the CCPi, there have been over 350 attending training courses; each year over 300 attend the three tomography-week events; 510 attendees at the 56 monthly seminars and a growing 400 email opt-in list. We have supported two spin-out companies and three members of the Working Group have been promoted to professors.

EPSRC Software as an Infrastructure strategy

Not only does this CCP assist and aid some of the major national facilities but also utilises related infrastructures including compute clusters within STFC and in the EPSRC Tier 2 regions. Following the mantra "Better Software Better Research" we have members who have fellowships within the SSI (Software Sustainability Institute), the ATI (Alan Turing Institute); and work closely with the newly formed RSE (Research Software Engineering) Society. We are also aware of the further overlaps with proposed CCPs including; CCP PET/MR, and CCP EM; and components of the code is being developed through projects with the Ada Lovelace Centre, Royce Institute and Alan Turing Institute.
Internationally we have representation and collaboration with Europe and have new links with Kitware Inc (TomViz and Paraview, Marcus Hanwell) and Oregon State University (DCV library, Brian Bay).

Finally, visual information can be a great aid to understanding ('seeing is believing') so this project will deliver results that can be appreciated by the novice as well as the expert. To this end it will have a significant public engagement mission. In the last Phase CCP code was involved in two Royal Society Exhibitions, the Cheltenham Science Festival and numerous open and outreach days - 13,750 visitors passed through the exhibition site at the Festival.