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a Chapter 7 Three-dimensional Color and Power Doppler Ultrasonography of the Fetal Cardiovascular System 89
Table 7.2. Conditions for potential 3D power Doppler application
in the abdominal region
Abnormal cord insertion on the abdomen (omphalocele,
gastroschisis), abnormal shape of the umbilical vein size
(varix or ectasia)
Ductus venosus agenesis with persistent right umbilical
vein
Agenesis of the portal vein
Abdominal vessels in malformations, congenital diaphragmatic
hernia, severe ascites, etc.
Abnormal course of vessels in isomerism, i.e., interruption
of inferior vena cava with azygous continuity
Single umbilical artery and abnormalities in lower abdomen
Fig. 7.9. In the same view as Fig. 7.8, 3D PDU demonstrates
in this case an agenesis of the left umbilical artery.
Only one (dilated right) artery can be seen in its course to
the umbilical ring
cava, and the abdominal aorta. Using this technique
it is also possible to display the normal course of
umbilical arteries around the urinary bladder
(Fig. 7.8). Since Doppler studies of the ductus venosus
in growth-restricted fetuses is becoming an important
field in prenatal medicine, abnormalities of
the intrahepatic venous system are frequently detected
(Fig. 7.10) [16]. This anatomical region is,
however, complex, and it has been shown that 3D
Power Doppler can help in the differentiation between
anomalies (Table 7.2).
Renal Vessels
The renal vascular tree is best visualized in a coronal
plane (Fig. 7.11). Depending on velocity scale setting,
vessels can be seen from the main artery with some
ramifications to the peripheral cortical vessels including
arteries and veins. The visualization of renal vessels
is known to increase the accuracy of diagnosis of
kidney malformations in the fetus. The examiner
should be, however, aware of pitfalls such as the visualization
of the ventrally situated abdominal arteries
(inferior mesenteric artery and vessels from celiac
trunk) that can be misinterpreted as renal arteries.
Conditions in which 3D PDU could be of diagnostic
value are listed in Table 7.3.
Fig. 7.10. Abnormal course of the intraabdominal umbilical vein and ductus venosus in a fetus with early hydrops at
13 weeks