Objective:

To analyze the magnetic resonance imaging (MRI) findings of synovial sarcoma (SS) for deepening the knowledge of SS and improving the diagnostic accuracy.

Methods:

The MRI features of 26 cases with histologically proven SS were reviewed. The differences of MRI features between different subtypes of SS

and between different locations were explored.

Results:

A total of 26 cases

20 were periarticular

and the other 6 cases were non-periarticular. The masses showed mainly iso- or slightly hyper- signal intensity (SI) on T1-weighted imaging

(T1WI)

heterogeneous hyper- SI on T2-weighted imaging (T2WI)

and heterogeneous notable enhancement. Twenty-two cases were found with fibrous septa

19 with necrosis/cystic degeneration

5 with fluid-fluid level

19 with the sign of nodular accumulation

and 19 with triple sign. There were no significant differences in the MRI features between spindle cell and biphasic type SS

and between periarticular SS and non-periarticular SS. Moreover

there were moderate positive correlations between the presence of the nodular accumulation sign

triple sign

and the tumors size (

r

=0.73

P

=0.002 9).

Conclusion:

SS usually shows characteristic MRI features

so most are allowed for a definite diagnosis. There are moderate positive correlations between the presence of MRI features and the tumors size. No remarkable differences in MRI features of SS can be seen either in different pathological subtypes or in different locations.