title: MRI in the diagnosis and surgical management of abnormal placentation.
abstract: OBJECTIVE
  To determine the usefulness of placental magnetic resonance imaging (MRI) in the diagnosis and surgical management of abnormal placentation.
  
  
  METHODS
  Retrospective follow-up.
  
  
  METHODS
  Buenos Aires, Argentina.
  
  
  METHODS
  547 pregnant women.
  
  
  METHODS
  In all cases, a direct and reliable description of abnormal placentation features was obtained by the operating surgeon. Placental MRI was analyzed according to: (1) primary description, (2) invasion topography, (3) modification required to the surgical tactics or techniques and (4) by positive and negative predictive values.
  
  
  METHODS
  Ultrasound and MRI findings were compared with surgical results, which were considered a final diagnosis in relation to primary diagnostic indications.
  
  
  RESULTS
  Placental MRI was obtained because of diagnostic doubt in 78 cases, for deep invasion diagnosis in 148 cases and to define the invasion area in 346 cases. Placental MRI allowed accurate demarcation and assessment of the degree of placental invasion, parametrial involvement and cervico-trigonal vascular hyperplasia, permitting changes in the surgical tactical approach. Ultrasound and MRI differences were associated with placenta previa, uterine scar thinning and use of different criteria for placental invasion through definitions or terminology. Six cases of false-negative and 11 of false-positive findings were reported.
  
  
  CONCLUSIONS
  Placental MRI provides excellent characterization of the degree and extension of placental invasion. Its usefulness in cases of adherent placentation is directly associated to the therapeutic measures, especially where dissection maneuvers are needed. Diagnostic differences between ultrasound and MRI related to the presence or not of placenta previa and uterine scar thinning.
authors.affiliation: South Scientific Foundation, Lomas de Zamora, Buenos Aires, Argentina. jpalacios@fmed.uba.ar
authors.forename: José Miguel
authors.initials: JM
authors.lastname: Palacios-Jaraquemada
authors.forename: Claudio Hernán
authors.initials: CH
authors.lastname: Bruno
authors.forename: Eduardo
authors.initials: E
authors.lastname: Martín
mesh_terms: D000328:Adult; D016063:Blood Loss, Surgical / Q000517:prevention & control*; D002585:Cesarean Section; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007044:Hysterectomy; D008279:Magnetic Resonance Imaging; D010921:Placenta Accreta / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000601:surgery*; D011247:Pregnancy; D011256:Pregnancy Outcome; D011296:Prenatal Diagnosis; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014463:Ultrasonography; D055815:Young Adult