IMAGING OF PLACENTAL VASCULATURE USING 3-DIMENSIONAL ULTRASOUND AND COLOR POWER DOPPLER - A PRELIMINARY-STUDY

Objective To assess placental vasculature using color power Doppler an d three-dimensional ultrasound techniques. Design A prospective study was performed in patients to correlate visualization of placental vess els in vivo with known anatomy. Subjects Fourteen normal patients and one patient with intrauterine growth restriction were recruited to the study. Methods Vessels were assessed with regard to, first, the numbe r of vessels seen within the placenta, second, the branching pattern o f the vessels within the placenta, third, the number of vessels seen a long the surface of the placenta, and, last, the number of vessels see n in the maternal circulation. Results Our results show that the place ntal vessels seen with this technique correlate well with known anatom y. A progressive increase in the number of intraplacental vessels and the number of vascular branches observed was seen with increasing gest ational age. Volume data review using three orthogonal planar images h ad two distinct advantages. First, they could be obtained from orienta tions Not possible using two-dimensional ultrasound alone, and, second , they could be viewed in conjunction with volume-rendered images to a llow for referencing and identification of specific vessels. Volume-re ndered images were valuable in allowing the observer to acquire an imp roved overall understanding of placental anatomy. They also assisted t he observer in following the continuity of vessels as they wrapped aro und and twisted through three-dimensional space. Stereo viewing was he lpful in distinguishing overlapping vessels. Conclusions Our study sho wed that sonographic volume imaging combined with color power Doppler imaging methods allowed for individual vessels in the placenta to be i dentified both in the fetal and maternal circulations.