• Fun Facts

    Post
    Australians are exposed to 2 millisieverts of 'background' radiation per year
    Post
    A CT of the chest can be roughly equivalent to having 100 single chest X-rays
    Post
    15x Melbourne → Singapore → London flights exposes you to 1 millisievert
  • Diagnostic X-rays

    A diagnostic X-ray is the oldest and most common medical radiology procedure. Radiologists use X-rays to help diagnose disease or injury inside your body. A machine directs a small, carefully calculated amount of radiation toward a specific part of the body to produce an image on a film on the other side of the body. Radiologists study the X-ray images to detect and diagnose disease or injury.

  • CT dosage

    Computed Tomography (CT) is currently one of the major contributors to the collective population radiation dose due to the increasing popularity of CT examinations as a non-invasive diagnostic tool. The evolution of CT scanner technology has turned their use from specialized into routine examination. More due diligence is required due to the high radiation dose of CT.

  • Where to from here?

    It is of the utmost importance that both clinical justification as well as technical optimization are implemented to maintain a high benefit to risk ratio. Solid interdisciplinary partnerships and research endeavours between clinical specialists and technology engineers will help to fast track developments in this area.

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LDI Profile

photo-charlene1

Charlene Stahr

Former LDI Office Manager and Research Administrator

Dept. Mechanical & Aerospace Engineering, Monash University Clayton Campus

Qualifications:

BEng(Mech, Hons) Monash 2008, BTech(Aero) Monash 2008

Research Interests:

Functional lung imaging, respiratory disease models, Laboratory Management; OHS, ethics, research administration, laboratory protocol and procedure. Biological sample preparation, design and manufacture of synchrotron apparatus.

  Please visit our Research page to see some videos of LDI's collaborative research endeavours.

Publications/Conferences/Seminars:

  1. Stahr, C.S., Samarage, C.R., Parsons, D.W., Dubsky, S., Donnelley, M., Thurgood, J.B., Henon, Y., Siu, K.K.W. & Fouras, A. (2014) Regional image based pulmonary function testing detects CF lung disease earlier than conventional PFT. Proc. American Thoracic Society 2014 International Conference — ATS 2014, San Diego, California, U.S.A., American Journal of Respiratory and Critical Care Medicine, 189, A2837. (16–21 May 2014).
  2. Donnelley, M., Morgan, K.S., Siu, K.K.W., Farrow, N., Stahr, C.S., Boucher, R.C., Fouras, A. & Parsons, D.W. (2014) Non-invasive airway health assessment: Synchrotron imaging reveals effects of rehydrating treatments on mucociliary transit in-vivo. Scientific Reports, 4, 3689.
    doi: 10.1038/srep03689
  3. Donnelley, M., Morgan, K.S., Siu, K.K.W., Farrow, N., Chua, C.S., Fouras, A. & Parsons, D.W. (2013) In-vivo changes in mucociliary transport after aerosol. Abstracts of the Thoracic Society of Australia & New Zealand and the Australian & New Zealand Society of Respiratory Science 2013 Annual Scientific Meetings, Darwin, NT, Australia, Respirology, 18, 2, p14. (22–27 Mar 2013)
    doi: 10.1111/resp.12045
  4. Siu, K.K.W., Chua, C.S., Parsons, D.W., Donnelley, M., Morgan, K.S., Farrow, N. & Fouras, A. (2012) Regional measures of lung function in the ß–ENaC mouse obtained using X-ray image velocimetry. 26th Annual North American Cystic Fibrosis Conference — NACFC 2012, Orlando, Florida, U.S.A, 11–13 October 2012.
  5. Chua, C.S., Higgins, S. & Fouras, A. (2010) An asynchronous high-speed synchrotron shutter. Journal of Synchrotron Radiation, 17, 624–630.
    doi: 10.1107/S0909049510025847
  6. Higgins, S., Chua, C.S., Hourigan, K. & Fouras, A. (2010) A sub-millisecond asynchronous X-ray shutter (The Absence of Light: A high speed shutter used for ultra-fast imaging and dose control for X-ray beams), in the Poster Session for The Meetings of Biology and Synchrotron Radiation & Medical Applications of Synchrotron Radiation — BSR 2010 & MASR 2010, Melbourne, Australia, 16–19 February 2010.
  7. PDF Download Chua, C.S., Sheard, G.J., Dubsky, S., Higgins, S., Jamison, R.A., Fouras, A. & Hourigan, K. (2009) Particle image velocimetry of non-axisymmetric stenosis models, in Proc. 8th International Symposium on Particle Image Velocimetry — PIV09, Melbourne, Australia, 25–28 August 2009.
  8. PDF Download Chua, C.S., Sheard, G.J., Ryan, K. & Fouras, A. (2009) Changes in flow and wall shear stresses through arterial constrictions offset from the vessel centre, ANZIAM Journal, 50, C744–C759.
    Also in Proc. 14th Biennial Computational Techniques and Applications Conference (CTAC'08), Australian National University, Canberra, ACT, Australia, 13–16 July 2008.

Masters topic:

Regional CF-like lung disease detection using 4D synchrotron X-ray CT

Details:

Structural changes in the lung tissue of patients with cystic fibrosis lung disease alter the flow of air and motion in the lungs, whether caused by obstruction, increasing airway resistance, or by changes to the lung parenchyma altering the mechanical properties of the tissue. Altered lung motion is therefore an indicator of disease. X-ray velocimetry (XV), is a new and emerging imaging technique for biomedical research from roots in fluid dynamics to trace fluidic motion. It combines synchrotron-based phase contrast X-ray imaging and statistical particle image velocimetry (PIV), to trace motion within the body. By utilizing XV, motion within the lung is measured at thousands of points across the lung in 4 dimensions (3 spatial dimensions over time), providing highly sensitive regional information about lung function, akin to spirometry performed at each and every point in the lung.

High speed X-ray shutter

Experiments performed at synchrotrons are not only stressed for time, but equipment and specimens are exposed to high and continuous doses of X-ray radiation. In order to save expensive imaging equipment and biological specimens from destructive radiation damage, an X-ray shutter must be implemented between the X-ray beamline and the specimen/detector. The high-speed X-ray shutter must operate reliably (good repeatability), provide sufficient X-ray attenuation, have an opening/closing time as fast as possible, and operate with precise timing so that it can be synced accurately with the camera's exposure times and frame rates.

Mach 3 of LDI's X-ray shutter utilises moving parts which operate at over 100G's of acceleration, to produce sub-millisecond opening or closing times for a 4mm x 6mm aperture. The electronic controls for the X-ray shutter are currently being redesigned at Monash University.

Haemodynamics of obstructed vessels

Arterial disease is the leading cause of death in the developed world. A common form of arterial disease is atherosclerosis; a progressive degenerative disease where plaques form on the inner surfaces of arteries — comprising of an abnormal accumulation of inflammatory cells, lipids and connective tissue. The presence of an arterial constriction, often called stenoses, sees normal blood flow disturbed as the haemodynamic effects of the flow are influenced. The downstream flow will subsequently be more turbulent, causing different conditions at the downstream pipe wall.

By modelling stenoses of different eccentricities and geometries, both computationally and experimentally, the physical severity of stenoses may be assessed based on flow parameters such as vorticity, wall shear and recirculation stagnation, of which are experienced by the downstream vessel wall.