Aw. Welsh et al., Freehand three-dimensional Doppler demonstration of monochorionic vascularanastomoses in vivo: a preliminary report, ULTRASOUN O, 18(4), 2001, pp. 317-324
Objectives To demonstrate the three-dimensional vascular anatomy of monocho
rionic placental anastomoses in vivo, both arterioarterial and arteriovenou
s.
Design Two-dimensional placental mapping techniques were used to locate art
erioarterial 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 fl
ow) using purpose-designed software (CQ analysis) and the files reconstruct
ed into a three-dimensional volume, for multidirectional viewing and movie
generation.
Results Both arterioarterial and arteriovenous anastomoses could be visuali
zed in detail. Reconstruction of a dual volume of gray-scale and segmented
color images allowed recreation of the vascular anatomy within the placenta
l substance, as well as retention of the original directional flow informat
ion.
Conclusions Detailed anastomotic anatomy can be demonstrated three dimensio
nally in vivo. Given the increasing evidence implicating various anastomoti
c configurations in pathological intertwin transfusion, this technique may,
prove useful in the antenatal assessment and treatment of monochorionic tw
in pregnancies.