Philip Lee1, Johannes Riegler2,
Bingwen Zheng1, Anthony Price2, Mark F. Lythgoe2,
Xavier Golay3
1Singapore Bioimaging Consortium,
Biomedical Sciences Institute, Singapore, Singapore; 2Centre for
Advanced Biomedical Imaging, University College London, London, United
Kingdom; 3Institute of Neurology, University College London,
London, United Kingdom
Migration
of super-paramagnetic labeled cells critically affects the success of
therapeutic cell studies. Detection with T2* weighted MRI is normally
implemented. But direct association of signal voids with SPIOs-labeled cells
is erroneous, as they could originate from magnetic field inhomogeneities or
partial volume effects. This study highlights the use of a multiple-echo
ultra-short echo time (MUTE) sequence for positive contrast visualization of
injected mononuclear cells. 5x105 and 2.5x105 of MNCs were directly injected
into the left myocardium wall at the apex and mid-ventricle respectively and
the heart was subsequently excised for MRI. Subtraction between the UTE
(TE=0.208ms) and ECHO (TE=2.56ms) images exploited the transverse relaxation
effect of iron, generating contrast-to-noise ratio of 19.6 and 22.7
respectively.