Rationale and Objectives. For diagnosis, preoperative planning and postoperative guides, an accurate estimate of joint kinematics is required. It is important to acquire joint motion actively with real-time protocols. Materials and Methods. We bring together MRI developments and new image processing methods in order to automatically extract active bone kinematics from multi-slice real-time dynamic MRI. We introduce a tracking algorithm based on 2D/3D registration and a procedure to validate the technique by using both dynamic and sequential MRI, providing a gold standard bone position measurement. Results. We present our technique for optimizing jointly the tracking method and the acquisition protocol to overcome the trade-off in acquisition time and tracking accuracy. As a case study, we apply this methodology on a human hip joint. Conclusion. The final protocol (bFFE, TR/TE 3.5/1.1 ms, Flip angle 80°, pixel size 4.7 × 2.6 mm, partial Fourier reduction factor of 0.65 in read direction, SENSE acceleration factor of 2, frame rate = 6.7 frames/s) provides sufficient morphological data for bone tracking to be carried out with an accuracy of 3° in terms of joint angle. © AUR, 2005.
Gilles, B., Perrin, R., Magnenat-Thalmann, N., & Vallee, J. P. (2005). Bone motion analysis from dynamic MRI: Acquisition and tracking. In Academic Radiology (Vol. 12, pp. 1285–1292). https://doi.org/10.1016/j.acra.2005.08.006