Simon Walker-Samuel1, Rajiv Ramasawmy1, Peter Johnson2, Jack Wells1, Bernard Siow1, Barbara Pedley2, Mark F. Lythgoe1
1Centre for Advanced Biomedical Imaging, University College London, London, United Kingdom; 2Cancer Institute, University College London, United Kingdom
Tumours exhibit raised interstitial fluid pressure (IFP), which acts as a barrier to drug delivery and results in convection currents that radiate from the centre of the tumour to the periphery. We report a novel method named extra-vascular convectography (EVAC) for measuring interstitial fluid velocity (IFV), that does not require a contrast agent, and have evaluated it in two tumour models. The method consists of vascular nulling using a double inversion preparation, a recovery delay, and a velocity encoding readout. Using EVAC we have identified both radial and laminar interstitial convection patterns with a median velocity of 0.28 mm/s.