title: Three-Dimensional Power Doppler Ultrasonography for Diagnosing Abnormally Invasive Placenta and Quantifying the Risk.
abstract: OBJECTIVE
  To test an objective ultrasound marker for diagnosing the presence and severity of abnormally invasive placenta.
  
  
  METHODS
  Women at risk of abnormally invasive placenta underwent a three-dimensional power Doppler ultrasound scan. The volumes were examined offline by a blinded observer. The largest area of confluent three-dimensional power Doppler signal (Area of Confluence [Acon], cm) at the uteroplacental interface was measured and compared in women subsequently diagnosed with abnormally invasive placenta and women in a control group who did not have abnormally invasive placenta. Receiver operating characteristic curves were plotted for prediction of abnormally invasive placenta and abnormally invasive placenta requiring cesarean hysterectomy.
  
  
  RESULTS
  Ninety-three women were recruited. Results were available for 89. Abnormally invasive placenta was clinically diagnosed in 42 women; 36 required hysterectomy and had abnormally invasive placenta confirmed histopathologically. Median and interquartile range for Acon was greater for abnormally invasive placenta (44.2 [31.4-61.7] cm) compared with women in the control group (4.5 cm [2.9-6.6], P<.001) and even greater in the 36 requiring hysterectomy (46.6 cm [37.2-72.6], P<.001). Acon rose with histopathologic diagnosis: focal accreta (32.2 cm [17.2-57.3]), accreta (59.6 cm [40.1-89.9]), and percreta (46.6 cm [37.5-71.5]; P<.001 analysis of variance for linear trend). Receiver operating characteristic analysis for prediction of abnormally invasive placenta revealed that with an Acon of 12.4 cm or greater, 100% sensitivity (95% confidence interval [CI] 91.6-100) could be obtained with 92% specificity (95% CI 79.6-97.6); area under the curve is 0.99 (95% CI 0.94-1.0). For prediction of abnormally invasive placenta requiring hysterectomy, 100% sensitivity (95% CI 90.3-100) can be obtained with an Acon of 17.4 cm or greater with 87% specificity (95% CI 74.7-94.5; area under the curve 0.98 [0.93-1.0]).
  
  
  CONCLUSIONS
  The marker Acon provides a quantitative means for diagnosing abnormally invasive placenta and assessing severity. If further validated, subjectivity could be eliminated from the diagnosis of abnormally invasive placenta.
  
  
  METHODS
  II.
authors.affiliation: Nuffield Department of Obstetrics & Gynaecology, University of Oxford, and the Fetal Medicine Unit, John Radcliffe Hospital, Oxford, and the Evelyn Perinatal Imaging Centre, Rosie Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom; and the Center for Abnormal Placentation, Division of Maternal Fetal Medicine and Surgery, Department of Obstetrics and Gynecology, Hackensack University Medical Center, Hackensack, New Jersey.
authors.forename: Sally L
authors.initials: SL
authors.lastname: Collins
authors.forename: Gordon N
authors.initials: GN
authors.lastname: Stevenson
authors.forename: Abdulla
authors.initials: A
authors.lastname: Al-Khan
authors.forename: Nicholas P
authors.initials: NP
authors.lastname: Illsley
authors.forename: Lawrence
authors.initials: L
authors.lastname: Impey
authors.forename: Leigh
authors.initials: L
authors.lastname: Pappas
authors.forename: Stacy
authors.initials: S
authors.lastname: Zamudio
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D016001:Confidence Intervals; D005260:Female; D005865:Gestational Age; D006801:Humans; D007044:Hysterectomy; D021621:Imaging, Three-Dimensional; D015588:Observer Variation; D010921:Placenta Accreta / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D010922:Placenta Diseases / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D011237:Predictive Value of Tests; D011247:Pregnancy; D012372:ROC Curve; D012016:Reference Values; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D018615:Ultrasonography, Doppler, Color / Q000379:methods*; D016216:Ultrasonography, Prenatal / Q000379:methods; D055815:Young Adult