Diagnosis of Struma ovarii with medical imaging.

Objective: To analyze the imaging features of Struma ovarii (SO), and to correlate the imaging results with the pathological findings so as to enhance the knowledge of the imaging diagnostics of this disease.

Methods: The clinical records, CT and MRI features of twelve patients with pathologically proved SO were retrospectively analyzed. Imaging features were compared with pathological results.

Results: Most tumors (n = 11, 91.7%) were unilateral. In CT and MRI images, the lesions presented as defined irregularly shaped masses, showing mainly cystic (n = 6, 50%) or cystic (n = 6, 50%). The cystic portions presented as well defined, multiple, various size, and a whole cyst wall with smooth inner wall. Eight cases of tumors (66.7%) showed a high attenuation lesion in the cyst portion of the mass on CT precontrast scans, in which two cases showed high signal on T1WI and low signal on T2WI. The solid portions, which distributed in the cyst showed irregular tissue density. After contrast administration, the cystic portions showed no enhancement, the solid portions marked enhancement, and the cyst wall demonstrated no, moderate, or marked enhancement. Eight cases of tumors (66.7%) showed stippled calcification in the cyst wall. Four cases of tumors (33.3%) accompany a great of abdominal dropsy and pleural fluid.

Conclusions: In general, SO appeared as a smooth marginated multicystic mass with a high attenuation lesion on precontrast scans on CT scans, and signal intensities on T1-weighted images were partly intermediate to high, or high, and those on T2-weighted images were low. The CT and MRI characteristic findings of SO might be of great value for the diagnosis.