title: Struma ovarii: MR appearances.
abstract: BACKGROUND
  Analysis of unenhanced and contrast-enhanced magnetic resonance (MR) images of struma ovarii, a rare benign neoplasm of the ovary, is the aim of this study.
  
  
  METHODS
  T2-weighted and Gd-DTPA-enhanced T1-weighted MR images of five histologically proven struma ovarii were evaluated retrospectively.
  
  
  RESULTS
  In all patients, unenhanced and contrast-enhanced T1-weighted MR images showed complex cystic masses composed of multiple cysts and a solid component, indicating the presence of large and small thyroid follicles. In four patients, the cyst fluid was hypointense on T1-weighted images and hyperintense on T2-weighted images. In one patient, the fluid was hyperintense on T1-weighted images and hypointense on T2-weighted images due to hemorrhage.
  
  
  CONCLUSIONS
  A complex mass composed of multiple cysts and a solid component, indicating the presence of large and small thyroid follicles, appeared to be a characteristic MR finding of struma ovarii.
authors.affiliation: Department of Radiology, Kumamoto University School of Medicine, 1-1-1 Honjo, Kumamoto 860, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Yamashita
authors.forename: Y
authors.initials: Y
authors.lastname: Hatanaka
authors.forename: M
authors.initials: M
authors.lastname: Takahashi
authors.forename: K
authors.initials: K
authors.lastname: Miyazaki
authors.forename: H
authors.initials: H
authors.lastname: Okamura
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media; D005260:Female; D005682:Gadolinium; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009942:Organometallic Compounds; D010051:Ovarian Neoplasms / Q000175:diagnosis*; D004369:Pentetic Acid / Q000031:analogs & derivatives; D012189:Retrospective Studies; D013330:Struma Ovarii / Q000175:diagnosis*
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; D004369:Pentetic Acid; D005682:Gadolinium; D019786:Gadolinium DTPA