Measuring in-vivo, loaded knee kinematics through dynamic MRI

Understanding normal and impaired musculoskeletal function during motion is a high radiological, biomechanical and clinical priority [1]. Understating the joint kinematics under loads is a fundamental step. Actual measurement techniques are however invasive or imprecise [2]. Dynamic magnetic resonance imaging (DMRI) represents an edging technology that may overcome these limitations, providing a way to record the motion of articular structures non-invasively [3]. This work presents a combination of MRI scanner (0.25 T G-Scan Brio, Esaote), MRI compatible rig (fig. 1.a), MR dynamic sequence (2D-HYCE S Gradient Echo), and postprocessing software (a 2D/3D registration algorithm based on edge detection and ICP registration) that makes it possible to measure the tibio-femoral relative motion in-vivo, under physiological loading conditions and over 90° of knee flexion.