Sub voxel position identification in Cadmium Zinc Telluride detectors for Low Dose Molecular Breast Imaging
Lead Research Organisation:
University of Liverpool
Department Name: Physics
Abstract
This knowledge exchange project seeks to develop an optimised Cadmium Zinc Telluride (CZT) system for low dose molecular breast imaging (MBI). Breast cancer is the most common type of cancer in the UK, with 1 in 8 women developing the disease. Approximately 50% of women of screening age have mammographically dense breasts but conventional X-ray mammography has reduced diagnostic performance for these patients. This limitation can be overcome by using MBI, a technique in which a molecular tracer selectively targets malignant breast tissue to provide high-resolution functional images. Earlier diagnosis and more accurate staging of the disease using optimised MBI systems will potentially lead to better patient outcomes and reduced mortality rates. The proposed research will improve the imaging performance of MBI, which will increase the probability of detecting lesions in the breast. This will be based on exploiting our knowledge of how radiation interacts in the imaging system.
Publications
McAreavey Lucy H.
(2019)
Development of the DEPICT system for gamma-ray imaging in molecular radiotherapy
Rintoul E
(2021)
Characterisation of the charge collection properties in a segmented planar HPGe detector
in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Rintoul E
(2022)
Simulation and validation of a planar HPGe detector signal database for use in pulse shape analysis
in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Rintoul E
(2023)
Sub-voxel identification of gamma-ray interaction positions within a pixelated CZT detector through signal analysis
in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
| Description | The project demonstrated that sub voxel position resolution can be achieved using analysis of the signal shapes from the detector. Precision databases of signal shapes were produced from a variety of detectors and the work has strengthened collaboration with the industrial partner. The work has been used to underpin preliminary follow on studies of how to improve the sustainability of detectors through recovering radiation damage performance using signal analysis. |
| Exploitation Route | The techniques could be applied in pixellated CZT detectors for various applications in which they are used for radiation imaging. |
| Sectors | Aerospace Defence and Marine Energy Healthcare Security and Diplomacy |
| Description | Digital Nuclear Measurement Training of Practitioners in the Nuclear Sector |
| Geographic Reach | National |
| Policy Influence Type | Influenced training of practitioners or researchers |
| Impact | Delivered several training workshops for members of the nuclear sector to develop skills and knowledge relevant to Digital signal processing with radiation detectors. This included the participants logging in remotely to operate and acquire data with radiation detectors in Liverpool. There were also seminars aimed at developing knowledge and skills in this area as well as showcasing the research activities in several funded UKRI projects, relevant to the topic. |
| Description | STFC Cancer Diagnosis Network+ |
| Amount | £486,977 (GBP) |
| Funding ID | ST/S005404/1 |
| Organisation | Science and Technologies Facilities Council (STFC) |
| Sector | Public |
| Country | United Kingdom |
| Start | 06/2019 |
| End | 07/2024 |
| Description | Sub-voxel position identification in Cadmium Zinc Telluride detectors for Low Dose Molecular Breast Imaging |
| Amount | £545,073 (GBP) |
| Funding ID | 2112967 |
| Organisation | Science and Technologies Facilities Council (STFC) |
| Sector | Public |
| Country | United Kingdom |
| Start | 09/2018 |
| End | 03/2022 |
| Description | The Tale of Two Tunnels |
| Amount | £99,465 (GBP) |
| Funding ID | ST/S000127/1 |
| Organisation | Science and Technologies Facilities Council (STFC) |
| Sector | Public |
| Country | United Kingdom |
| Start | 04/2018 |
| End | 04/2023 |
| Title | CZT signal database |
| Description | Experimental database for charge signals inside a pixellated CZT detector, acquired using collimated gamma-ray sources. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2020 |
| Provided To Others? | No |
| Impact | Not known |
| Title | Charge Signal Database for Small Pixel Camera |
| Description | Datasets have been produced for the CZT small pixel camera procured in this capital grant. These have been collected using collimated high activity gamma sources including 57Co and 137Cs. The databases show how the signals respond in groups of pixels for known gamma-ray interaction positions and are been used to achieve sub voxel position resolution in the detectors. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2022 |
| Provided To Others? | No |
| Impact | Used to improve the performance of the detectors and to evaluate sub-voxel position sensing algorithms for small pixel cameras |
| Title | Charge Trapping and Transport Model |
| Description | A model has been created that allows calculation of charge transport within semiconductor detectors, based upon pre-simulated potentials. The model implements probabilistic charge trapping, detrapping, and recombination based upon user defined values (drawn from literature). Use of the model allows correction for simulated databases to account trapping physics. |
| Type Of Material | Computer model/algorithm |
| Year Produced | 2023 |
| Provided To Others? | No |
| Impact | Model has been used to account for previously ignored physics in simulated charge-transport databses - allowing for accurate simulation of physical detector systems. This will be used to provide the basis of a publication, with the goal being public release of the model for research purposes. |
| Title | Experimental Signal Database for a CZT Detector |
| Description | High-precision collimated scans of a 22 x 22 x 5 mm CZT crystal were performed. A digital acquisition system was used to record data from 3x3 pixel clusters. Two pixel clusters were scanned with a collimated Am-241 source producing signal databases representing the crystal's surface response. One pixel cluster was side-scanned with a collimated Cs-137 source to produce a signal database representing the crystal's depth response. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2020 |
| Provided To Others? | No |
| Impact | The implementation of signal analysis techniques that rely on the characterised signal response of a detector have been developed and implemented, enabling achievement of sub-poxel position resolution within the detector. |
| Description | eV Products (Kromek USA) |
| Organisation | eV Products, Inc |
| Country | United States |
| Sector | Private |
| PI Contribution | A PhD student from the project team went to eV products in USA for 3 weeks to conduct NEMA tests of a CZT SPECT system. |
| Collaborator Contribution | The partners financed the cost of the student visit, including hotel and travel. They also provide supervision and we are continuing to analyse the results following the visit. |
| Impact | The results are currently under analysis. It is expected they will be publishable. The student also developed new skills. |
| Start Year | 2016 |
| Description | A-Level Work Experience Week |
| Form Of Engagement Activity | Participation in an open day or visit at my research institution |
| Part Of Official Scheme? | No |
| Geographic Reach | Regional |
| Primary Audience | Schools |
| Results and Impact | Over the course of a week 5 students, originating from schools in the wider local region, took part in placements within the nuclear physics group. Activities included working with radiation detectors, analysing data, and discussion radiation measurement applications. Students reported a keen interest in attending the University of Liverpool for undergraduate degrees in physics, citing the hands-on experience with laboratory research equiptment as a major reason. |
| Year(s) Of Engagement Activity | 2022 |
| Description | Continuing Professional Development Radiation Detection Workshop for Nuclear Industry Professionals |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Industry/Business |
| Results and Impact | A CPD training workshop aimed at Nuclear Industry Professionals was developed for online delivery. The course contained online material as well as live laboratory sessions in which a demonstrator performed experimental work at the attendee's requests. Material covered the principles of radiation detection, gamma-ray and neutron spectroscopy, and digital electronics and analysis techniques (namely methods of pulse shape analysis in semiconductor detectors). The course attracted 29 participants from a number of backgrounds who engaged with both the online material and the laboratory sessions. Participants engaged in discussion during laboratory session relating to digital acquisition and processing techniques. They expressed interest in attending future courses that provide practical experience in modern radiation detection methods. |
| Year(s) Of Engagement Activity | 2020 |
| URL | https://livradiometrics.com/ |
| Description | Early Career Engagement Event |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Postgraduate students |
| Results and Impact | Presented a talk and participated as a panelist at an early Career Event for postgraduate and postdoctoral researchers at the Institute of Physics in London. |
| Year(s) Of Engagement Activity | 2021 |
| Description | Medical applications seminar to undergraduate students at the University of Liverpool |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Local |
| Primary Audience | Undergraduate students |
| Results and Impact | 29 3rd and 4th year undergraduate students attended a talk presenting the research topic covered by this grant (molecular breast imaging with CZT). Interest was expressed by a student in completing an MPhys research project on the topic in their next year of study and discussion was generated with students via email. |
| Year(s) Of Engagement Activity | 2022 |
| Description | Nuclear Physics Masterclass - Online course and resources on nuclear physics created and delivered to A-level students |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Schools |
| Results and Impact | The Nuclear Physics Masterclass was delivered entirely through developed online resources this year due to COVID restrictions. A website, online resources, worksheets, careers showcase, and educational games were developed. The sessions covered a range of nuclear-related topics including nuclear instability and shapes, gamma-ray shielding and detection, and nuclear applications with a large emphasis on medical uses and doses. The website attracted more than 1,500 unique visitors, hailing from 38 countries. Of these, 880 downloaded the worksheets and model answers. The course ended with an essay competition in which more than 70 people entered. The essay showed large engagement from students who performed independent and voluntary research into nuclear physics for their entries. The 1st and 2nd place prizes of the essay competition included access to a mentor at the University of Liverpool and provides continued engagement with nuclear physics for the two students. The UK schools involved in the masterclass reported a desire to be involved in future years. The delivery of the material through online resources allowed a larger engagement than is typically possible through face-to-face delivery, as well as increasing the range of schools from across the UK that are able to take part. |
| Year(s) Of Engagement Activity | 2020 |
| URL | https://livnuclear.co.uk/ |
| Description | STFC CDN+ Launch Event |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Other audiences |
| Results and Impact | The STFC Cancer Diagnosis Network+ was successfully launched on 9th September 2019. More than 90 national and international delegates attended the launch event at the University of Liverpool with attendees from universities, STFC facilities, industry, and healthcare. Leading expert's gave thought-provoking talks on each of the network's key challenge themes. The event was also a great networking opportunity for attendees to create new 'Cancer Diagnosis' links that will hopefully emerge as future research collaborations. |
| Year(s) Of Engagement Activity | 2019 |
| URL | https://sites.google.com/view/stfccancerdiagnosis/home/workshops |
| Description | STFC Cancer Diagnosis Challenge Workshop |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Other audiences |
| Results and Impact | STFC Challenge workshop 1 took place on campus in Leicester on Monday 20th January 2020. The event focused on 'Precision and Quantitative Imaging'. It was a great success with over 50 delegates attending from academic, clinical and industrial backgrounds. IOP Award winning Dr Dimitra Darambara chaired the day, introducing the four distinguished speakers; Prof Phil Allport, Dr Malene Fischer, Prof Nigel Allison and Dr Calum Williams. Network opportunities were also built into the day, with the group being divided up into smaller groups to start new techonology conversations and help establish new collabortions going forward. |
| Year(s) Of Engagement Activity | 2020 |
| URL | https://sites.google.com/view/stfccancerdiagnosis/home/workshops |
| Description | STFC Cancer Diagnostic Network+ Virtual Challenge Workshop - Early Diagnosis |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Other audiences |
| Results and Impact | The event focused on the theme of 'Early Diagnosis'. It was a half-day session, that included thought provoking speakers, a question and answer session, facilitated breakout rooms and an opportunity to engage with key industrial exhibitors. The event was Chaired by our CDN+ 'Early Diagnosis' theme lead Prof Nandita de Souza, with Co-Chair Prof John Lees. There was a funding call announcement for CDN+ Proof of Concept and Scoping Studies opened at the event. The event will helped establish further multidisciplinary collaborations between academic, clinicians and industry members to work together and address clinical challenges in the diagnosis of cancer. |
| Year(s) Of Engagement Activity | 2020 |
| URL | https://sites.google.com/view/stfccancerdiagnosis/home/workshops |
| Description | School Visit (Ballycastle) |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | Regional |
| Primary Audience | Schools |
| Results and Impact | 50 pupils attended a seminar delivered at Cross and Passion School, Ballycastle. After the seminar, emails were received from teachers and parents of pupils who attended. The school also posted on social media about the seminar. |
| Year(s) Of Engagement Activity | 2022 |
| Description | Seminar to undergraduate students at University of West Scotland |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Local |
| Primary Audience | Undergraduate students |
| Results and Impact | Seminar on the development of DEPICT for dose verification of radionuclide therapy. The audience was mainly undergraduate students, none of whom are from my institution. There was an increase in interest in medical applications of nuclear physics and a number of students asked for more information and to read my publications and book. |
| Year(s) Of Engagement Activity | 2019 |
| Description | Talk at Liverpool Cancer Research Institute |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | Regional |
| Primary Audience | Professional Practitioners |
| Results and Impact | Approximately 80 people attended a talk at the Liverpool Cancer Research Institute Symposium, including patient groups and Clinicians. Several follow up discussions, including around patient involvement in ongoing research projects and increased awareness of technical innovations to Clinicians. |
| Year(s) Of Engagement Activity | 2021 |
| Description | Talk at STFC Knowledge Exchange Event "Collaborating with industry and the NHS to develop next generation medical imaging systems" |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Industry/Business |
| Results and Impact | Talk at a knowledge exchange event to showcase how research projects have been developed in collaboration with the NHS and radiation detector industry. Discussed timescales and advised on challenges faced, to encourage other multidisciplinary activities. |
| Year(s) Of Engagement Activity | 2019 |