Xin Tian1,2, Hua Li1, Xiaoyu Jiang1, Jingping Xie1, John C Gore1, and Junzhong Xu1
1Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States, 2Radiology, The Second Hospital of Hebei Medical University, Shijiazhuang, China, People's Republic of
Two diffusion-based
method, the CG (constant gradient) and FEXI (filtered exchange imaging) methods, have been developed to provide a flexible and safer means to
measure transcytolemmal water exchange rate $$$k_{in}$$$
non-invasively in vivo. However, neither methods have been fully validated up
to date. In the present work, computer simulations and in vitro experiments
with well-controlled cultured cells with different sizes and permeabilities
were performed to evaluate the accuracy of the CG and FEXI methods. The results
suggest that $$$k_{in}$$$ can
be accurately estimated when $$$k_{in}$$$ < 10 Hz. Although the FEXI method provides less accurate results,
the linear dependence of AXR on $$$k_{in}$$$ suggesting it is still a reliable method.
