o_1977r8vv9vk1ts2ms0kd8pksa.pdf

a Chapter 31 Doppler Examination of the Fetal Pulmonary Venous Circulation 461
Fig. 31.21. Infracardiac TAPVC. Left: At
first sight analysis of pulmonary venous
connection may suggest a normal connection.
Right: Increasing velocity range
demonstrates that both veins are draining
into a vessel behind the atrium (arrows).
In another plane this vein is seen
crossing the diaphragm (see Fig. 31.23)
Rare Anomalies of the Pulmonary Veins
Other anomalies of the pulmonary venous system are
the presence of arteriovenous fistulae within the lung.
In the past few years there have been some case reports
of such conditions leading prenatally to volume
overload [27, 28]. The hint for detection was sonolucent
echoes in the lung showing a high turbulent flow
on color Doppler (Fig. 31.24). Another rare condition
is the direct connection of the pulmonary artery
branch directly to the left atrium bypassing the vein
as we described in a case report within a series of
different cases of cardiomegaly [29].
Fig. 31.22. Infracardiac TAPVC. Spectral Doppler of the intrathoracic
vein shows a continuous flow instead of the
pulsatile flow as sign of a abnormal connection (compare
with Figs. 31.7 and 31.19)