Effects of cell volume fraction changes on apparent diffusion in human cells

Diffusion-weighted imaging was used to study the relationship between appar ent diffusion coefficient (ADC) and cell volume fraction in cell suspension s and packed arrays. Cell volume fraction was varied by changing extracellu lar fluid osmolarity (for human glial cells) and by changing cell density ( far human glial and red blood cells). In packed arrays of glial cells, ADC increased 10% when cells shrank and decreased 13% when cells swelled. ADC d ecreased 34% as cell density increased from 0 to 72%. In erythrocyte suspen sions, ADC decreased 90% as the cell density increased from 0 to 89%. These results agree with theoretical predictions. (C) 2000 Elsevier Science Inc. All rights reserved.