The ultrasound (US) features of struma ovarii are nonspeciﬁc, but a heterogeneous, predominantly solid mass may be seen. US demonstrates a complex appearance with multiple cystic and solid areas, ﬁndings that reﬂect the gross pathologic appearance of the tumor.
Magnetic resonance imaging ﬁndings may be more characteristic: The cystic spaces demonstrate both high and low signal intensity on T1- and T2-weighted images. Some of the cystic spaces may demonstrate low signal intensity on both T1- and T2-weighted images due to the thick, gelatinous colloid of the struma. No fat is evident in these lesions.