Mueller matrix decomposition of diffuse reflectance imaging in skeletal muscle.

Propagation of polarized light in skeletal muscle is significantly affected by anisotropic muscle structures. To completely characterize muscle polarization properties, we acquired the whole Mueller matrix images of the diffuse reflectance. A polar decomposition algorithm was applied to extract the individual diattenuation, retardance, and depolarization images from the measured Mueller matrix. The decomposed polarization properties in muscle show distinctly different patterns from those obtained in isotropic scattering media. Stretching the prerigor muscle sample induced clear changes in the raw polarization reflectance images. However, muscle stretching induced minimal changes in the decomposed Mueller matrix images.