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[Humeroradial plica: frequency and visualization on MRI].

PURPOSE
To determine frequency and size of a humeroradial plica and correlate it with degenerative changes, and to determine frequency of the visualization of a synovial fold on MR-Images (T1-weighted spin-echo and STIR sequences) and correlate it with degenerative changes.


MATERIALS AND METHODS
Forty-two elbow specimens were dissected and studied for humeroradial synovial folds (small, medium, large) and degenerative changes (absent, medium, strong), and 88 elbow MR-images were analyzed for a synovial fold (not visible, small, large) and degenerative changes (absent, medium, strong). Comparison was performed using the chi (2) test.


RESULTS
Dissections revealed a synovial fold in all cases. The sizes were small in n = 13 (31 %), medium in n = 24 (57 %), and large in n = 5 (12 %). Degenerative changes were absent in n = 9 (21.4 %), medium in n = 29 (69 %), and strong in n = 4 (9.6 %). On MRI the synovial fold was not visible in n = 67 (76 %), small in n = 12 (14 %), and large in n = 9 (10 %). Degenerative changes on MRI were absent in n = 65 (74 %), medium in n = 15 (17 %), and strong in n = 8 (9 %). The size of the fold correlated positively with degenerative changes in the specimen but not with degenerative changes on MRI. The T1-SE sequence was superior to the STIR sequence in revealing the synovial fold.


DISCUSSION
A humeroradial plica is a regular finding, but visualized by MRI in only approximately 20 %, probably due to its variable size. Its visualization succeeds best with T1-spin-echo sequences.