title: Freehand three-dimensional Doppler demonstration of monochorionic vascular anastomoses in vivo: a preliminary report.
abstract: OBJECTIVE
  To demonstrate the three-dimensional vascular anatomy of monochorionic placental anastomoses in vivo, both arterioarterial and arteriovenous.
  
  
  METHODS
  Two-dimensional placental mapping techniques were used to locate arterioarterial and arteriovenous anastomoses. A freehand sweep was performed across the anastomotic site, and multiple images were stored to disk, at 17 Hz. These were then segmented to show only color information (vascular flow) using purpose-designed software (CQ analysis) and the files reconstructed into a three-dimensional volume, for multidirectional viewing and movie generation.
  
  
  RESULTS
  Both arterioarterial and arteriovenous anastomoses could be visualized in detail. Reconstruction of a dual volume of gray-scale and segmented color images allowed recreation of the vascular anatomy within the placental substance, as well as retention of the original directional flow information.
  
  
  CONCLUSIONS
  Detailed anastomotic anatomy can be demonstrated three dimensionally in vivo. Given the increasing evidence implicating various anastomotic configurations in pathological intertwin transfusion, this technique may prove useful in the antenatal assessment and treatment of monochorionic twin pregnancies.
authors.affiliation: Department of Maternal and Fetal Medicine, Queen Charlotte's and Chelsea Hospital, Institute of Reproductive and Developmental Biology, Imperial College School of Medicine, London. UK. a.welsh@ic.ac.uk
authors.forename: A W
authors.initials: AW
authors.lastname: Welsh
authors.forename: M J
authors.initials: MJ
authors.lastname: Taylor
authors.forename: D
authors.initials: D
authors.lastname: Cosgrove
authors.forename: N M
authors.initials: NM
authors.lastname: Fisk
mesh_terms: D001159:Arterio-Arterial Fistula / Q000000981:diagnostic imaging*; D001164:Arteriovenous Fistula / Q000000981:diagnostic imaging*; D005260:Female; D005315:Fetal Diseases / Q000000981:diagnostic imaging*; D005330:Fetofetal Transfusion / Q000000981:diagnostic imaging; D006801:Humans; D021621:Imaging, Three-Dimensional; D010920:Placenta / Q000098:blood supply; D011247:Pregnancy; D012984:Software; D014427:Twins; D018615:Ultrasonography, Doppler, Color / Q000379:methods*; D016216:Ultrasonography, Prenatal / Q000379:methods*