title: Ovarian cysts on prenatal MRI.
abstract: OBJECTIVE
  Ovarian cysts are the most frequently encountered intra-abdominal masses in females in utero. They may, at times, require perinatal intervention. Using magnetic resonance imaging (MRI) as an adjunct to ultrasonography (US) in prenatal diagnosis, we sought to demonstrate the ability to visualize ovarian cysts on prenatal MRI.
  
  
  METHODS
  This retrospective study included 17 fetal MRI scans from 16 female fetuses (23-37 gestational weeks) with an MRI diagnosis of ovarian cysts after suspicious US findings. A multiplanar MRI protocol was applied to image and to characterize the cysts. The US and MRI findings were compared, and the prenatal findings were compared with postnatal imaging findings or histopathology.
  
  
  RESULTS
  Simple ovarian cysts were found in 10/16 cases and complex cysts in 7/16 cases, including one case with both. In 11/16 (69%) cases, US and MRI diagnoses were in agreement, and, in 5/16 (31%) cases, MRI specified or expanded the US diagnosis. In 6/16 cases, postnatal US showed that the cysts spontaneously resolved or decreased in size, and in 1/16 cases, postnatal imaging confirmed a hemorrhagic cyst. In 4/16 cases, the prenatal diagnoses were confirmed by surgery/histopathology, and for the rest, postnatal correlation was not available.
  
  
  CONCLUSIONS
  Our results illustrate the MRI visualization of ovarian cysts in utero. In most cases, MRI will confirm the US diagnosis. In certain cases, MRI may provide further diagnostic information, additional to US, which is the standard technique for diagnosis, monitoring, and treatment planning.
authors: Department of Radiology, Division of Neuroradiology and Musculoskeletal Radiology, Medical University Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria. stefan.nemec@meduniwien.ac.at
authors: Ursula
authors: U
authors: Nemec
authors: Stefan F
authors: SF
authors: Nemec
authors: Dieter
authors: D
authors: Bettelheim
authors: Peter C
authors: PC
authors: Brugger
authors: Ernst
authors: E
authors: Horcher
authors: Veronika
authors: V
authors: Schöpf
authors: John M
authors: JM
authors: Graham
authors: David L
authors: DL
authors: Rimoin
authors: Michael
authors: M
authors: Weber
authors: Daniela
authors: D
authors: Prayer