title: Evaluation of interobserver variability and diagnostic performance of developed MRI-based radiological scoring system for invasive placenta previa.
abstract: To evaluate the interobserver variability and diagnostic performance of a developed magnetic resonance imaging (MRI)-based scoring system for invasive placenta previa.
  
  
  
  Prenatal MR images of 70 women were retrospectively evaluated, 18 of whom were diagnosed with invasive placenta. The six MR features (dark band on T2 -weighted images, intraplacental abnormal vascularity, placental bulge, heterogeneous placenta, myometrial thinning, and placental protrusion sign) were scored on 5-point Likert scale separately, and the cumulative radiological score (CRS) was defined as the sum of each score. Two more experienced radiologists (readers A and B) and two less experienced residents (readers C and D) calculated the CRS. Interobserver variability was assessed by measuring the intraclass correlation coefficient. Diagnostic performance was evaluated by means of receiver operating characteristic (ROC) analysis.
  
  
  
  Interobserver variability for CRS was excellent for the more experienced radiologists (0.85), and good for all readers (0.72) and the less experienced residents (0.66). The area under the ROC curve (Az) and accuracy (Acc) for CRS were significantly higher or equivalent to those of other MR features for all readers (Az and Acc for reader A; CRS, 0.92, 91.4%; intraplacental T2 dark band, 0.83, P = 0.009, 81.4%, P = 0.03; intraplacental abnormal vascularity, 0.9, P = 0.3, 90.0%, P = 1.00; placental bulge, 0.81, P = 0.0008, 80.0%, P = 0.02; heterogeneous placenta, 0.85, P = 0.11, 74.3%, P = 0.002; myometrial thinning, 0.84, P = 0.06, 60.0%, P < 0.0001; placental protrusion sign, 0.81, P = 0.01, 81.4%, P = 0.26).
  
  
  
  This developed MRI-based scoring system demonstrated excellent or good interobserver variability, and good diagnostic performance for invasive placenta previa. J. Magn. Reson. Imaging 2016;44:573-583.
authors.affiliation: Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Ueno
authors.affiliation: Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Maeda
authors.affiliation: Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Utaru
authors.initials: U
authors.lastname: Tanaka
authors.affiliation: Department of Obstetrics and Gynecology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Tanimura
authors.affiliation: Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan.|Department of Nuclear Medicine and PET Center, Hyogo College of Medicine, Nishinomiya, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kitajima
authors.affiliation: Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Suenaga
authors.affiliation: Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Takahashi
authors.affiliation: Department of Obstetrics and Gynecology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Hideto
authors.initials: H
authors.lastname: Yamada
authors.affiliation: Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Kazuro
authors.initials: K
authors.lastname: Sugimura
mesh_terms: D000328:Adult; D000465:Algorithms; D002983:Clinical Competence; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015588:Observer Variation; D010923:Placenta Previa / Q000000981:diagnostic imaging* / Q000473:pathology*; D011247:Pregnancy; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
keywords: MRI; invasive placenta; placenta accreta; placenta previa; prenatal diagnosis