Value of Dynamic Enhanced MR Imaging for the Differential Diagnosis between Ovarian Fibroma and Subserosal Leiomyoma

OBJECTIVE To study the value of dynamic enhanced MR imaging in the differential diagnosis between ovarian fibroma and subserosal leiomyoma, both of which produce a intermediate to low signal intensity on T2WI.

METHODS Plain and dynamic enhanced MRI results of 45 patients were analyzed, 35 cases of which were subserosal leiomyoma and 10 were ovarian fibroma. All of the tumors were verified by histologic analysis.

RESULTS The 10 ovarian fibroma cases showed low signal intensities on T1WI, but 2 produced intermediate signal intensities and 8 showed low signal intensities on T2Wl. There was little enhancement of the early phase and the delayed phase was long, so the enhancement index of the early phase (Sl100) was low and the time to peak (TTP200) was long. Of the 35 subserosal leiomyoma cases, all showed low signal intensity on T1WI, 7 were intermediate in signal intensity and 28 generated a low signal intensity on T2WI. The enhancement of the early phase was moderate to highly evident and the index was high. The time to peak was short (TTP200). The enhancement-time curve was different in the two groups, and the difference had statistical significance (P<0.001).

CONCLUSION Dynamic enhanced MR imaging was helpful in the differential diagnosis between ovarian fibroma and subserosal leiomyoma by the difference of the early phase enhancement.