Changes in Diffusion Properties of Biological Tissues Associated with Mechanical Strain(Biomagnetism and Medical Application)

Mechanical strain in biological tissues causes a change in the diffusion properties of water molecules. This paper proposes a method of estimating mechanical strain in biological tissues using diffusion magnetic resonance imaging (MRI). Measurements were carried out on uncompressed and compressed chicken skeletal muscles. A theoretical model of the diffusion of water molecules in muscle fibers was derived based on Tanner’s equation. Diameter of the muscle fibers was estimated by fitting the model equation to the measured signals. Changes in the mean diffusivity (MD), the fractional anisotropy (FA), and diameter of the muscle fiber did not have any statistical significance. The intracellular diffusion coefficient (Dint) was changed by mechanical strain (p<.05). This method has potential applications in the quantitative evaluation of strain in biological tissues, a though it poses several technical challenges.