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.