Dynamic magnetic resonance imaging technique for the study of the temporomandibular joint

Aims: Echo planar imaging (EPI) is an ultrafast magnetic resonance imaging (MRI) technique that can scan a single frame in less than a second. The aim of this study was to use the EPI technique to develop a new dynamic MRI pr otocol for the temporomandibular joint (TMJ). Methods: Basic fast-field ech o and EPI pulse sequences were used for dynamic studies of the TMJ. The sub jects were instructed to perform spontaneous, continuous, slow opening/clos ing movements without visual or audio feedback. Different scanning paramete r settings were explored to optimize the results. Results: With an opening/ closing movement of approximately 6 to 7 seconds per cycle, the proposed pr otocol yielded a good insight into the relative motion between condyle and disc. It was also possible to see the deformation of the disc during moveme nt. Conclusion: The EPI technique is a non-invasive technique that can be u sed for dynamic imaging study of a slow but continuous, uninterrupted jaw m ovement.