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

10 25 50

publication icon
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

publication icon
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

publication icon
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

 
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 07/2019 
End 07/2023
 
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 £77,545 (GBP)
Funding ID ST/S000127/1 
Organisation Science and Technologies Facilities Council (STFC) 
Sector Public
Country United Kingdom
Start 05/2018 
End 04/2020
 
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