title: Twin-twin transfusion syndrome: cerebral ischemia is not the only fetal MR imaging finding.
abstract: BACKGROUND
  Twin-twin transfusion syndrome (TTTS) is a complication of monochorionic/diamniotic twin pregnancies. An imbalance of blood flow occurs through placental anastomoses, causing potentially significant morbidity and mortality in both twins. Although the sonographic findings of TTTS are well documented, we believe that MR imaging is a valuable adjunct.
  
  
  OBJECTIVE
  We describe the fetal MR imaging findings associated with TTTS.
  
  
  METHODS
  From 2003 to 2005, 37 consecutive MR imaging studies were performed on multiple-gestation pregnancies. Of the 37, 25 were consistent with TTTS, correlated and confirmed by sonographic criteria. MR fetal abnormalities were documented.
  
  
  RESULTS
  Cerebral ischemia, which could not be demonstrated by sonography, was delineated well by MR imaging. New findings noted on fetal MR imaging were enlargement of cerebral venous sinuses in both twins, dilatation of the renal collecting system in the recipient, lung lesions in the recipient and cerebral malformations in the donor.
  
  
  CONCLUSIONS
  MR imaging is an important adjunct in TTTS imaging. Its benefit over sonography is its clear definition of cerebral pathology, which is important for intervention and counseling. The new findings, particularly in the urinary tract and cerebral venous sinuses, also help support the diagnosis of TTTS and might reveal additional consequences of the altered hemodynamics that occur in TTTS.
authors.affiliation: Department of Radiology, Cincinnati Children's Hospital Medical Center, University of Cincinnati Medical Center, Cincinnati, OH, USA.
authors.forename: Beth M
authors.initials: BM
authors.lastname: Kline-Fath
authors.forename: Maria A
authors.initials: MA
authors.lastname: Calvo-Garcia
authors.forename: Sara M
authors.initials: SM
authors.lastname: O'Hara
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Crombleholme
authors.forename: Judy M
authors.initials: JM
authors.lastname: Racadio
mesh_terms: D002545:Brain Ischemia / Q000175:diagnosis* / Q000000981:diagnostic imaging; D005260:Female; D005313:Fetal Death; D005330:Fetofetal Transfusion / Q000175:diagnosis* / Q000000981:diagnostic imaging; D005865:Gestational Age; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D011247:Pregnancy; D011256:Pregnancy Outcome; D014430:Twins, Monozygotic; D016216:Ultrasonography, Prenatal