o_1977r8vv9vk1ts2ms0kd8pksa.pdf

178 P. Arbeille et al.
Fig. 13.1. Investigation of the fetal cerebral arteries (a, b).
Fetal cranial cross section with the cerebral peduncle and
the Doppler sample volume on the anterior cerebral arteries
and the corresponding Doppler spectrum. c, d Color
Doppler of the circle of Willis. e Three-dimensional color
Doppler
anterior to the cerebral peduncles, and the anterior
arteries are found on a line perpendicular to the previous
line approximately 2 cm in front of the peduncles'
anterior limit.
With color Doppler technology it became possible
to visualize and investigate the main cerebral arteries
and to evaluate vascular resistance in various vascular
areas of the brain supplied by these arteries [26]. In
Figure 13.1 the two anterior, middle, and posterior cerebral
arteries, and the posterior communicating arteries,
can be easily identified. The incidence displaying
these vessels is similar to the ªbiparietal incidenceº
used for measuring the fetal head diameter. The vessels
most easily investigated by this incidence are the middle
cerebral arteries, because they are oriented toward
the Doppler transducer. In this case the angle between
the vessel axis and the Doppler beam is close to zero
and the Doppler frequency is maximum.