Doctoral Candidates

Miss Jenna Arbid

Doctoral Candidate (USYD and NHMRC Scholarships)
School of Health Sciences, The University of Sydney

Thesis topic: Phase Contrast Computed Tomography of the Breast

Thesis abstract
Breast cancer is the most commonly occurring cancer in women worldwide and one of the two leading causes of cancer deaths in women. Digital Mammography, the current gold standard for breast cancer screening, is restrained by its low sensitivity and specificity. Sensitivity on average is 70% (50% amid women with high breast density), prompting false negative results and delayed treatment. The modality’s low specificity contributes to false positive results, forcing up to 10% of women to unnecessarily return for additional investigation. To combat low specificity, screening is recommended every 2 years ensuing continued radiation to the radiosensitive organ. In addition, the breast must be compressed to decrease superimposition leaving patients in discomfort and pain that can persist for up to four days post-screening, ultimately resulting in decreased attendance. A new screening and diagnostic tool is needed to overcome these limitations.
Phase-contrast computed tomography (PB-CT) is a novel low-dose, high-quality, three-dimensional imaging modality that produces imaging contrast via x-ray refraction in
addition to attenuation (absorption contrast). With varying models transitioning from non-living models to human excised tissue, PB-CT has been proven to have a better contrast-to-noise ratio in comparison to conventional x-ray imaging, consequently improving sensitivity and specificity. This study aims to refine imaging conditions for PB-CT, specifically tailoring them to accommodate variations breast density and size, and to establish the diagnostic efficacy of this promising modality.

Supervisors
Dr Seyedamir Tavakoli Taba
Prof Patrick Brennan
Dr Dania Abu Awwad
Prof Sarah Lewis

Mr Jannis Ahlers

Doctoral Candidate (RTP Scholarship)
School of Physics and Astronomy, Monash University

Thesis topic: Spectral coherent X-ray imaging of the lungs

Thesis abstract
X-ray imaging is the most widely used imaging technique world-wide; it is cheap, quick, and can provide high resolution. However, traditional attenuation-based X-ray imaging gives poor contrast in soft tissues. Novel modalities exploit the coherent refraction (phase-contrast) and scattering (dark-field) of X-rays in the sample, giving significantly improved contrast in soft and porous tissues. In-line X-ray imaging techniques allow for experimentally-simple reconstruction of phase contrast. I am interested in the extension of in-line techniques to dark-field imaging, and in particular how the spectral properties of the imaging system can be employed in solving the inverse problem of dark-field reconstruction. A simple and effective dark-field imaging technique would have a multitude of uses in medical, security, and industrial contexts. A key application is chest imaging, for the diagnosis and evaluation of lung diseases. I am involved in the lung imaging sub-project of the IMPACT programme, which is aiming to develop coherent in-line lung imaging at the Australian Synchrotron. 

Supervisors
Associate Professor Kaye Morgan
Associate Professor Konstantin Pavlov
Associate Professor Marcus Kitchen

Miss Lucy Costello

Doctoral Candidate (RTP Scholarship)
School of Physics and Astronomy, Monash University 

Thesis topic: Phase-Contrast Computed Tomography (PC-CT) for Clinical Cancer Diagnostics

Thesis abstract
Conventional x-rays are primarily used in medical applications to look for hard-tissue injuries like broken bones and tumours. But when it comes to soft-tissue, x-rays have difficulties resolving features well enough to be of sound clinical use. 
One of the main reasons that conventional x-rays have such a hard time capturing the detail of soft tissue structures and organs is due to their weakly-attenuating properties; meaning they are not dense enough for the x-rays to be absorbed and form a clear shadow image on the detector. Over the last 15 years, synchrotron-based Phase-Contrast X-ray Imaging (PCXI) has shown itself to be a powerful tool for capturing weakly-attenuating tissues in the body. PCXI achieves this by looking at the phase of the x-rays as well as the intensity of the x-rays. Two weakly-attenuating tissue types that are difficult to image using conventional x-ray imaging are the breast and lung. Both however, have shown significant contrast improvements when imaged with PCXI. 
If we couple the idea of PCXI with Computed Tomography (CT) we can develop a three-dimensional (3D) Phase-Contrast CT (PC-CT) image. By transforming current CT technology, we can take low radiation dose, high-resolution 3D images for clinical cancer diagnostics. With the use of the Australian Synchrotron, we aim to transform the diagnosis of breast and lung cancer using novel x-ray imaging methods.  

Supervisors
Associate Professor Kaye Morgan
Associate Professor Marcus Kitchen