Bernard Siow1, David W. Carmichael2,3, Johannes Riegler4, Daniel Alexander1, Mark Lythgoe4, Roger Ordidge3
1Centre for Medical Image Computing, University College London, London, United Kingdom; 2Institute of Neurology, University College London, United Kingdom; 3Department of Medical Physics and Bioengineering, University College London, United Kingdom; 4Centre for Advanced Biomedical Imaging, University College London, United Kingdom
The Sub-pixel Enhancement of Nonuniform Tissue (SPENT) sequence applies a 2pi phase dispersion across each voxel: the net phase of spins in magnetically homogeneous voxels would be equal to zero and thus no signal would be generated. If there are sub-pixel inhomogeneities, then the net phase of spins in a voxel is not zero and thus signal is seen. In this study, human mononuclear cells labelled with micron-sized iron oxide particles, which creates sub-voxel perturbations in the field, are scanned with a spin-echo SPENT sequence producing positive contrast images. SPENT provides directional information, as well as the potential for quantification.