Strain Rate Mapping of the Lower Leg Muscles During Plantarfelxion Excursion Using MR Velocity Mapping.

Usha Sinha¹, Ali Moghaddasi², Shantanu Sinha²

Strain rate describes the rate of regional deformation and does not require 3dal tracking, or a reference state since strain rate is an instantaneous measure of kinematic properties. Our focus was to extract strain rate from spatial gradients of the velocity vector calculated from velocity encoded PC images. A challenge is the noise in the gradient maps which was addressed with a novel application of an anisotropic diffusion filter. Strain rate maps were calculated in 5 normal subjects during ankle plantarflexion excursion. Compressive and expansive strain tensors could be visualized and revealed complex spatial patterns with temporal changes.