Computed Tomography at the Quantum Limit using Phase Contrast X-ray Imaging
The biggest problem with X-ray imaging in diagnostic medicine is the use of potentially dangerous ionizing radiation. Researchers across the globe are exploring Phase Contrast X-ray Imaging (PCXI) techniques to revolutionise X-ray imaging for applications in diagnostic imaging, materials science and security applications . PCXI modalities increase the contrast of interfaces between materials by rendering gradients in the X-ray wavefield visible. Its advent has had a profound impact in many fields of science from biomedical imaging to materials characterization for industrial research. Using synchrotron radiation, our team has shown that this sensitivity can increase the signal-to-noise ratio of 3D tomographic imaging (CT) by factors in the hundreds [2, 3]. Using synchrotron radiation, we have shown that the radiation dose can be reduced by factors in the tens of thousands without loss of image quality . Our aim is to develop this technology for use on non-synchrotron X-ray sources, with the goal of translating it for massively reducing the radiation dose in human diagnostic imaging.
This project will investigate the use of new laboratory-based, high powered, highly coherent X-ray sources for developing an ultra-low dose CT capability. These sources include the liquid metal jet anode X-ray source at Monash University. Using phase contrast images produces on these sources in combination with phase retrieval and iterative reconstruction algorithms, we aim to produce high quality 3D images of the inner structures of objects using extremely low doses of radiation.
An introduction to our research group including recent publications can be found here: https://xrayimagingmonash.wordpress.com/
Applicants should hold an Honours or Master’s degree in Physics or equivalent discipline. Interested applicants must meet Monash University's PhD entry requirements and may apply for scholarships. Scholarships cover tuition and health insurance costs (for international candidates) and provide a living stipend of AU$27,353 per year (http://www.monash.edu/graduate-research/future-students/apply), which can be increased to AU$32,000 with a J.L. Williams top-up scholarship (https://www.monash.edu/science/schools/physics/postgrad/postgraduate-scholarships).
If you have any questions, please contact Dr Marcus Kitchen ([Email Address Removed]).
1. Bravin, A., P. Coan, and P. Suortti, X-ray phase-contrast imaging: from pre-clinical applications towards clinics. Physics in Medicine and Biology, 2013. 58: p. R1-R35.
2. Beltran, M.A., et al., Interface-specific x-ray phase retrieval tomography of complex biological organs. Physics in Medicine and Biology, 2011, 56(23): p. 7353–7369.
3. Beltran, M.A., et al., 2D and 3D X-ray phase retrieval of multi-material objects using a single defocus distance. Optics Express, 2010, 18(7): p. 6423-6436.
4. Kitchen MJ, et al., CT dose reduction factors in the thousands using X-ray phase contrast. Scientific Reports, 2017, 7(1), 15953. (http://www.nature.com/articles/s41598-017-16264-x)