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Feasibility of using real‐time MRI to measure joint kinematics in 1.5T and open‐bore 0.5T systems
Author(s) -
Draper Christine E.,
Santos Juan M.,
Kourtis Lampros C.,
Besier Thor F.,
Fredericson Michael,
Beaupre Gary S.,
Gold Garry E.,
Delp Scott L.
Publication year - 2008
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.21413
Subject(s) - kinematics , imaging phantom , scanner , knee joint , joint (building) , accuracy and precision , rotation (mathematics) , computer science , match moving , magnetic resonance imaging , motion (physics) , biomedical engineering , computer vision , nuclear medicine , physics , artificial intelligence , mathematics , medicine , radiology , engineering , surgery , statistics , architectural engineering , classical mechanics
Purpose To test the feasibility and accuracy of measuring joint motion with real‐time MRI in a 1.5T scanner and in a 0.5T open‐bore scanner and to assess the dependence of measurement accuracy on movement speed. Materials and Methods We developed an MRI‐compatible motion phantom to evaluate the accuracy of tracking bone positions with real‐time MRI for varying movement speeds. The measurement error was determined by comparing phantom positions estimated from real‐time MRI to those measured using optical motion capture techniques. To assess the feasibility of measuring in vivo joint motion, we calculated 2D knee joint kinematics during knee extension in six subjects and compared them to previously reported measurements. Results Measurement accuracy decreased as the phantom's movement speed increased. The measurement accuracy was within 2 mm for velocities up to 217 mm/s in the 1.5T scanner and 38 mm/s in the 0.5T scanner. We measured knee joint kinematics with small intraobserver variation (variance of 0.8° for rotation and 3.6% of patellar width for translation). Conclusion Our results suggest that real‐time MRI can be used to measure joint kinematics when 2 mm accuracy is sufficient. They can also be used to prescribe the speed of joint motion necessary to achieve certain measurement accuracy. J. Magn. Reson. Imaging 2008;28:158–166. © 2008 Wiley‐Liss, Inc.