Kevin D. Harkins1,2, Jean-Phillipe Galons3,
Joseph L. Divijak1, Theodore P. Trouard1,3
1Biomedical Engineering, University of
Arizona, Tucson, AZ, United States; 2Vanderbilt University
Institute of Image Science, Vanderbilt University, Nashville, TN, United
States; 3Radiology, University of Arizona, Tucson, AZ, United
States
It
was initially discovered nearly two decades ago that the apparent diffusion
coefficient (ADC) drops 30-50% after the onset of ischemic stroke. Despite
its clinical utility, there is still no consensus on the biophysical cause of
the drop in the ADC. In this work, oscillating gradient and pulsed gradient
diffusion experiments were performed on perfused cell cultures to measure the
ADC of intracellular water over a wide range of diffusion times. Results
indicate that the biophysical mechanisms that influence ADC are diffusion
time dependent, where diffusion measured at short diffusion times is highly
sensitive to the intrinsic diffusion of intracellular water and the diffusion
measured at longer diffusion times is more sensitive to cell size.