Objective      To investigate the magnetic resonance imaging (MRI) characteristics of ovarian sex cord-stromal tumor (SCST).       Methods      The MRI findings of 31 cases of ovarian SCST in our hospital from January 2009 to August 2013 were reviewed retrospectively.       Results      The 31 cases of ovarian SCST included 9 cases of theca cell tumor

14 cases of fibrothecoma

6 cases of granulosa cell tumor and 2 cases of Sertoli-Leydig cell tumor. In the 23 cases of theca cell tumor and fibrothecoma

3 cases had solid and cystic lesion

1 case had completely cystic lesion

and 19 cases (82.61%) were solid (76.19% showed very low signal on T

2

WI and 23.81% showed slightly high signal; degeneration in the tumors were observe

d). The ovarian granulosa cell tumors presented mixed cystic-solid mass. After contrast administration

marked enhancement of solid components and septa in tumor was revealed. Two Sertoli-Leydig cell tumors also presented mixed cystic-solid mass. After contrast administration

the solid elements and septa had enhancement.       Conclusion      Ovarian SCST demonstrates variable MRI morphological appearances

and each type of the tumor has characteristic MRI features.