Hua Li1, Xiaoyu Jiang1, Jingping Xie1, John C Gore1, and Junzhong Xu1
Current
diffusion MRI methods that quantitatively characterize tissue microstructure
usually assume a zero transcytolemmal water exchange rate $$$\tau_{in}$$$
between intra- and extracellular spaces. This assumption may not be true in many
cases of interest. The present work used both computer simulations and cell
culture in vitro to investigate the influence of $$$\tau_{in}$$$ on
the accuracy of fitted microstructural parameters such as mean cell size $$$d$$$,
intracellular water fraction $$$f_{in}$$$ and
diffusion coefficient $$$D_{in}$$$.
Results indicate $$$d$$$ is relatively insensitive
to $$$\tau_{in}$$$, while $$$f_{in}$$$ is always
underestimated with finite $$$\tau_{in}$$$. $$$D_{in}$$$ can
be fit reliably only when short diffusion times are used.
