Figure 12c. Mature cystic teratoma of the left ovary. (a) Sagittal transabdominal US image shows a large, heterogeneous, predominantly hyperechoic mass (arrows). (b) Axial contrast-enhanced CT image shows the retrouterine mass (arrows), which is predominantly of fat attenuation. (c, d) Axial in-phase (c) and out-of-phase (d) MR images show signal loss at the interface between water- and lipid-based components on the out-of-phase image (arrows in d) relative to the signal intensity on the in-phase image (c), thus confirming the presence of a fat component. (e) Axial gadolinium-enhanced fat saturation T1-weighted MR image shows marked signal suppression (arrowheads).