title: MR Imaging of Fetuses to Evaluate Placental Insufficiency.
abstract: OBJECTIVE
  To evaluate morphological and signal intensity (SI) changes of placental insufficiency on magnetic resonance imaging (MRI) and to assess morphological changes and decreased flow voids (FVs) on T2-weighted rapid acquisition with relaxation enhancement (RARE) images for diagnosing placental insufficiency.
  
  
  METHODS
  Fifty singleton fetuses underwent MRI using a 1.5-T MR scanner. Placental thickness, area, volume, SI, amniotic fluid SI, and size of FVs between the uterus and the placenta were measured on MR images. Two radiologists reviewed T2-weighted RARE images for globular appearance of the placenta and FVs between the uterus and the placenta. Data were analyzed using t-tests, McNemar's tests, and areas under the receiver operating characteristic curve (AUCs) at 5% level of significance.
  
  
  RESULTS
  Twenty-five of the 50 pregnancies were categorized as having an insufficient placenta. Significant differences were observed between insufficient and normal placentas in mean placental thickness, area, volume, placenta to amniotic fluid SI ratio, and size of FVs (49.0 mm vs. 36.9 mm, 1.62 × 10(4) mm(2) vs. 2.67 × 10(4) mm(2), 5.13 × 10(5) mm(3) vs. 6.56 × 10(5) mm(3), 0.549 vs. 0.685, and 3.4 mm vs. 4.3 mm, respectively). The sensitivity and accuracy using globular appearance plus decreased FVs were greater than those using decreased FVs (P < 0.01). There was no significant difference among AUCs using globular appearance and decreased FVs, and globular appearance plus decreased FVs.
  
  
  CONCLUSIONS
  Placental insufficiency was associated with placental thickness, area, volume, placenta to amniotic fluid SI ratio, and size of FVs. Evaluating FVs on T2-weighted RARE images can be useful for detecting placental insufficiency, particularly in placentas without globular appearance on MR images.
authors.affiliation: Department of Radiology, Showa University School of Medicine.
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Ohgiya
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nobusawa
authors.forename: Noritaka
authors.initials: N
authors.lastname: Seino
authors.forename: Osamu
authors.initials: O
authors.lastname: Miyagami
authors.forename: Naomi
authors.initials: N
authors.lastname: Yagi
authors.forename: Sasamori
authors.initials: S
authors.lastname: Hiroto
authors.forename: Jiro
authors.initials: J
authors.lastname: Munechika
authors.forename: Masanori
authors.initials: M
authors.lastname: Hirose
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Takeyama
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Ohike
authors.forename: Ryu
authors.initials: R
authors.lastname: Matsuoka
authors.forename: Akihiko
authors.initials: A
authors.lastname: Sekizawa
authors.forename: Takehiko
authors.initials: T
authors.lastname: Gokan
mesh_terms: D005260:Female; D005333:Fetus / Q000000981:diagnostic imaging*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010927:Placental Insufficiency / Q000000981:diagnostic imaging*; D011247:Pregnancy