1Cardiff University, CUBRIC, Cardiff, United Kingdom, 2Department of Neurobiology, Tel Aviv University, Tel Aviv, Israel
With the increasing popularity of multi-shell diffusion techniques to
measure axonal density and diameter, the investigation of the exact origin of
the contrast has become a hot topic. Here, we investigate the impact of the
echo time in measuring the axonal density and show that the two water
compartments are characterised by a different relaxation time T2, making the
measures of the volume strongly dependent on the echo time. This suggests
caution when comparing data acquired with different setups and introduces a new
way of measuring the differential T2 properties of intra- and extra-axonal
water pools.
