The arthrographic and MRI findings of 44 joints suspected of having internal derangements were compared. MRI is markedly superior in detection of the changes in disc position and shape as compared to arthrography, especially the changes in the
shape and
the mediolateral dispalcement of the disc, which make it useful when the replacement of the disc is attempted. Furthermore, the osseous changes anterosuperior to the mandibular condyle can be visualized for the prediction of the progression of
arthrosis. However, the preforation and adhesion of the disc and the retrodiscal tissue are yet to be successfully visualized asccurately on MRI. The arthrography has been used since the second half of the 1970s for the visualization of the
internal
derangements. The procedure can provide accurate informations concerning the anterior-posterior position and the reduction of the disc. However, the shape of the disc is not visualized, and the mediolateral displacement cannot be diagnosed
accurately
from the edge sign of the arthrography alone. Despite the shortcomings, the arthrograhy can still provide informations in the diagnosis of the disc perforations and the dynamics of the disc movements better than MRI. The procedure also provide
some
limited informations concerning the disc adhesion through the findings when the dye is being injected. The two procedures each have their own advantages and shortcomings. The decision to use which method may depend on the ease of the application
in
each
case, and for the suspected condition further tests using the other method may yield more accurate diagnosis.
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