371: Visualization of first trimester fetal anatomy from random 3D volumes in correlation with gestational age


      To determine the success rate of visualizing fetal anatomy from first trimester 3D volumes obtained irrespective of fetal lie or position in correlation with gestational age.

      Study Design

      Transabdominal random 3D volumes were obtained from 109 patients at chorionic villus sampling, nuchal translucency screening, or dating scan between 10 0/7 – 14 2/7 wks gestation. Volumes were analyzed by a single trained examiner in 3 orthogonal planes using 4D view software for 19 anatomic structures, as defined by AIUM criteria for standard examination of fetal anatomy.


      Overall visualization success rates of anatomic structures increased from 28.9% to 72.4%, at 10 0/7 and 14 2/7wks, respectively (p<0.0001). The visualization rate of the posterior fossa, cavum septi pellucidi, 4-chamber heart, and cord vessels was less than 4%. The table lists the visualization rates for the other structures.
      Tabled 1Success Rates Between 11 and 13-6/7 Weeks
      11 to 11-6/713 to 13-6/7
      Choroid Plexus76.67%93.75%
      Cerebral Ventricles60.00%93.75%
      Midline Falx60.00%93.75%
      Cord Insertion56.67%68.75%
      Upper Spine73.33%100.00%
      Lumbar Spine60.00%87.50%
      Sacral Spine30.00%75.00%


      A substantial portion of fetal anatomic structures can be visualized by random 3D volumes with minimal acquisition time for post-hoc analysis and provide preliminary reassurance about fetal anatomy.