• Fun Facts

    Australians are exposed to 2 millisieverts of 'background' radiation per year
    A CT of the chest can be roughly equivalent to having 100 single chest X-rays
    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.


LDI Alumni Profile


Zac Ismadi

PhD graduate

Dept. Mechanical & Aerospace Engineering, Monash University Clayton Campus

Supervisors: Professor Andreas Fouras & Professor Kerry Hourigan


BEng(Mechanical, Hons) Monash 2010, PhD Monash 2015

PhD topic:

Mechanical properties characterisation of bioreactors for stem cell culture


The advent of stem cell research, especially the derivation of human pluripotent stem cells, such as human embryonic stem cells (hESC) and human induced pluripotent stem cells (hiPSC), has opened a new world in cell therapy and revolutionized regenerative medicine for many degenerative diseases or injuries. The stem cells' unlimited ability for self-renewal and differentiate to all cells type due to its undifferentiated state, make it an effective option as the basic material for various potential treatment. Even though many bioreactors have been designed, the knowledge of shear stress in stem cell cultivation protocol is still limited. The research is aimed to characterise the mechanical properties of various bioreactors to optimise cell culture procedure.


  1. Ismadi, M.Z.P., Higgins, S.P.A., Samarage, C.R., Paganin, D.M., Hourigan, K. & Fouras, A. (2013) Optimisation of a stirred bioreactor through the use of a novel Holographic Correlation Velocimetry flow measurement technique, PLoS One, 8(6):e65714.
    doi: 10.1371/journal.pone.0065714
  2. Hourigan, K., Ismadi, M.Z.P., Meunier, P. & Fouras, A. (2011) Vortex breakdown in bioreactors. International symposium on bifurcations and instabilities in fluid dynamics, Barcelona, 18–21 July 2011.
  3. Meunier, P., Ismadi, M.Z.P., Fouras, A. & Hourigan, K. (2011) Experimental control of vortex breakdown by density effects. EUROMECH Colloquium 525, Instabilities and transition in three-dimensional flows with rotation, Lyon, France, 21–23 June 2011.
  4. Ismadi, M.Z.P., Meunier, P., Fouras, A. & Hourigan, K. (2011) Experimental control of vortex breakdown by density effects. Physics in Fluids, 23(3), 034104.
    doi: 10.1063/1.3560386

Teaching experience:

  • Lab Demonstrator: MEC4418 Control Systems, Monash University Clayton (2011–2012)
  • Tutor and Lab Demonstrator: MEC2404 Fluid Mechanics I, Monash University Clayton (2012)
  • Tutor: MEC2404 Fluid Mechanics I, Monash University Clayton (2011)
  • Lab Demonstrator: MEC3458 Experimental Project, Monash University Clayton (2010–2011)
  • Tutor: MEC4418 Control Systems, Monash University Clayton (2010)
  • Tutor: MEC3457 Systems & Control, Monash University Clayton (2010)
  • Tutor: MEC4446 Composite Structures, Monash University Clayton (2010)