High-resolution temporal reconstruction of ankle joint from dynamic MRI

Cerebral palsy is the leading cause of motor disabilities affecting children. The ankle is the most common equine musculoskeletal strain in children with cerebral palsy. Despite multiple medical and surgical therapies, postoperative recurrence rate is still very high (48%). A major reason for therapy failure is the lack of knowledge of the ankle joint biomechanics. Dynamic MRI can be used to acquire high resolution static data and low resolution temporal images. However, spatial and temporal data should be combined to provide the most comprehensive point of view to study joint motion. In this paper, we first present an intensity-based registration method to accurately estimate the rigid motion of the ankle bones. Second, we investigate the use of the log-euclidean framework to reconstruct a four-dimensional (3D+time) high-resolution dynamic MRI sequence from a low-resolution dynamic sequence and one high resolution static MR image. The proposed approach has been applied and evaluated on in vivo MRI data acquired for a pilot study on child motor disability. Results demonstrate the robustness of the proposed pipeline and very promising high resolution visualization of the ankle joint.