Associate Professor Kaye Morgan is a lead investigator in the X-ray imaging group in the School of Physics and Astronomy at Monash University, recently completing a Future Fellowship from the Australian Research Council (ARC). Previous to this, Kaye held a Veski Postdoctoral Research Fellowship, spending several years at the Technische Universität München as a Hans Fischer Fellowship.  This followed an ARC Discovery Early Career Researcher Award, awarded in the year following her PhD. 

Kaye works in the field of x-ray optics, developing new methods of imaging that reach new scales in resolution, speed and sensitivity, and access new contrast modalities. One such modality is phase contrast x-ray imaging (PCXI), which examines changes in the x-ray phase rather than the x-ray intensity, revealing soft tissue structures like the airways that are not seen in conventional x-ray imaging. Another is x-ray dark-field imaging, which reveals where sub-pixel unresolved structures scatter the x-ray wavefield. Dr Morgan is working both on developing and extending these methods and on applying them to medical research questions. Imaging is performed largely at the SPring-8 synchrotron, the Australian Synchrotron and the Munich Compact Light Source.  

You can watch a brief description of her research here and find more detail here.

For most recent publications, see GoogleScholar.

• Single-grid/Speckle PCXI
  While many methods of PCXI offer either speed for dynamic imaging or high sensitivity in detecting subtle sample features, it is difficult to achieve both. Motivated by the challenge of imaging the liquid lining of the airways in real time, Dr Morgan developed single-grid imaging to realise sensitive high-speed x-ray movies (Optics Letters, Optics Express, Optics Letters, Optics Express).  She also demonstrated that this approach does not require a perfect grid pattern and can use the speckle pattern seen when illuminating a piece of paper (Applied Physics Letters, Journal of Synchrotron Radiation). This technique has also been applied to segment a sample into composite materials (Optics Letters). We have also been investigating novel approaches to retrieval that use physical models (see below) for low-dose imaging (Optica). Most recently, research has looked at how this technique can capture quantitative (Scientific Reports, Optics Express) and directional dark-field images (Optics Express).
  
  
• Propagation-based dark-field imaging
  We have also looked at how the sample can be used as its 'own' reference pattern to extract dark-field images without using any gratings or crystals. This approach is based on the X-ray Fokker-Planck Equation (see below), using either two propagation distances (IEEE Transactions on Medical Imaging, Optics Express) or two x-ray energies (Optica, Optics Letters).
  
  
• The application of PCXI to Respiratory Research
  Dr Morgan has been involved in applying these techniques to help biomedical research (SPIE proceedings, Journal of Synchrotron Radiation).  In collaboration with the Women's and Children's Hospital and the University of Adelaide, propagation-based and single-grid PCXI has been applied to study the airways affected by Cystic Fibrosis and the effectiveness for CF treatments (Journal of Anatomy, European Journal of Radiology). Collaborations with the Helmholtz Centre in Munich and Klinikum Rechts der Isar have looked at treatment delivery and clearance. Results have included imaging the clearance of debris along the airway surface (J. of Synchrotron Radiation, Respiratory Research), the delivery of treatments (Journal of Aerosol Medicine and Pulmonary Drug Delivery, Journal of Controlled Release), including magnetic guidance of treatment attached to nanoparticles (Scientific Reports, Physics in Medicine & Biology), motion of the lungs (Biomedical Optics Express, Scientific Reports, IEEE Transactions on Medical Imaging, Scientific Reports) and treatment-induced changes in the airway surface liquid (PLOS ONE, AJRCCM).  Most recently, we have captured time-resolved dark-field tomography of the lungs to track changes in alveolar size (IEEE TMI). This application-focused work has been covered in the media, including physicsworld (x2) and sciencedaily.
  
  
• Modelling and measuring coherent x-ray imaging set-ups
  Optimisation of PCXI is best performed with an accurate model of an x-ray source, the x-ray wavefield interactions and propagation, and the imaging system. This requires sound mathematical underpinnings, reasonable numerical models and careful measurements of the source characteristics.  Recent work looked at how the Fokker-Planck Equation can be applied to describe x-ray phase and dark-field (Scientific Reports, Scientific Reports, Physical Review A), and separate out edges from dark-field-inducing microstructure (Optics Express).  Dr Morgan has compared numerical models for x-ray wavefield propagation through a sample (the projection approximation) with exact solutions, plotting Cornu spiral-like phase contrast signatures in the Argand plane (Optics Express, Optics Communications). Measurements have looked at the effect of a diffuser, commonly used to even out illumination, with some consequences in terms of spatial coherence (Optics Express, Optics Communications).
  
  
• Translating techniques to compact x-ray sources for wider adoption
  Kaye is also looking at the translation of PCXI techniques from synchrotron sources to laboratory sources, for research accessibility and eventual clinical availability.  This work has used both the Excillum liquid metal jet source and the world's first source driven by Inverse Compton Scattering, the Munich Compact Light Source (Physics in Medicine and Biology, Scientific Reports, Scientific Reports, IEEE Transactions on Medical Imaging, Journal of Controlled Release, Scientific Reports).
  In parallel, we have been looking at how phase contrast can scale up to human imaging for diagnostics, at a whole-lung scale for screening (Scientific Reports), to examine suspicious masses at high resolution (Scientific Reports), or to realise virtual histology (Advanced Science).