4d in vivo non-invasive quantification of ankle joint space width using dynamic mri

Spatio-temporal evolution of joint space width (JSW) during motion is of great importance to help with early treatment plans for degenerative joint diseases like osteoarthritis (OA). However, only a few studies have attempted to quantify the JSW from moving joints and the accuracy of measurements always remains debatable. In this paper, we present a generic pipeline that can be useful to accurately determine the changes of the JSW during the joint motion cycle from dynamic MRI sequences. This is done using an Eulerian approach for solving partial differential equations (PDE) inside a moving inter-bone space where bone segmentations are considered as Dirichlet boundaries. The proposed approach was applied and evaluated on in vivo dynamic MRI data of five healthy children to quantify the spatio-temporal evolution of the JSW of the ankle (tibiotalar joint) during the entire dorsi-plantar flexion motion cycle.