Quantification of skin movements artefacts using MRI

we present a methodology for anatomical modeling, motion tracking and skin movement quantification of the hip joint using Magnetic Resonance Imaging. First, we capture the subject’s anatomy with a static protocol and reconstruct the three-dimensional models of the hip joint. Then reflective markers are attached to the subject’s limb and a dynamic protocol is used to track their trajectories. It is known that the skin surface deforms while in motion due to muscle contraction leading to errors in trajectories estimation. In this study, the displacements of the markers relative to the underlying bone are observed and quantified in all three axes. A statistical analysis is performed on the data and a strong correlation is determined between the skin movements and the instantaneous kinematics variables of the joint especially for hip rotations. The quantification of these errors could be used as a basis for a correction procedure for hip joint kinematics. Keywords-component; hip joint; MRI, skin aretefacts, statistical analysis;