Abstract #2566

Gravity Dependent Ventilation of Rats Measured by Hyperpolarised Helium MRI and Electric Impedence Tomography

Marlies Elly Joy Friese¹, Kimble R. Dunster,¹², Gary J. Cowin¹, Deming Wang¹, Graham Galloway¹, John Fraser^3,4, Andreas Schibler,^4,5

¹Centre for Magnetic Resonance, The University of Queensland, Brisbane, Queensland, Australia; ²Medical Engineering Research Facility,, Queensland University of Technology, Brisbane, Queensland, Australia; ³Paediatric Intensive Care Unit,, Mater Childrens Hospital, Brisbane, Queensland, Australia; ⁴Critical Care Research Group, The Prince Charles Hospital, Brisbane, Queensland, Australia; ⁵Paediatric Intensive Care Unit, Mater Childrens Hospital, Brisbane, Queensland, Australia

Gravity-dependent ventilation distribution was investigated in using both hyperpolarised helium-3 magnetic resonance imaging (HP3He MRI) and electrical impedance tomography (EIT). Time averaged EIT data and HP3HeMRI images of apnoea showed ventilation distribution in rats to be gravity dependent, whereas regional filling characteristics are dependent on anatomy. HP3He MRI and EIT data agree where they can be compared. HP3He MRI provides data on real geometry which EIT cannot as EIT tomograms are reconstructed to a circular image. Dynamic imaging of the breathing cycle with HP3He is still needed to make a full comparison of the two methods.