o_1977r8vv9vk1ts2ms0kd8pksa.pdf

580 I. Zalud
cavity is ªcoldº with respect to blood flow, diagnosis
of ectopic pregnancy is confirmed. It has been reported
to increase the diagnostic sensitivity of sonography
for ectopic pregnancy from 71% to 87% [32±
34]. It also helps eliminate the problem of false positives,
except in rare situations of ovarian pregnancy.
Kurjak et al. have reported on the difference between
the RI of the corpus luteum blood flow and
peritrophoblastic flow of the ectopic pregnancy. The
cutoff value for the RI of corpus luteum blood flow
has been described to be 0.4 and the RI of peritrophoblastic
blood flow below 0.4 [34]. Kirchler has described
the use of Doppler blood flow in measuring
the RI in tubal branches of the bilateral uterine arteries.
The vessel with low-resistance flow indicates
the side of the ectopic pregnancy [35].
Endometrial color flow/image-directed Doppler
imaging has also been reported to reduce the falsepositive
TVS examinations which occur in 5%±10%
of patients with high-risk findings. Ectopic pregnancy
has no intrauterine trophoblastic activity, hence the
presence of trophoblastic flow (arterial blood flow
within the endometrium) lowers the risk of ectopic
pregnancy whether an intrauterine gestational sac is
present or not. However, care must be taken to ensure
that arterial and not venous flow signals are obtained.
The Doppler cursor should be completely within the
endometrium to ensure that the signal is endometrial
Fig. 39.15. High-velocity/low-impedance
(RI=0.42) blood flow signals are
obtained from the color-coded area
and represent active, invasive trophoblast
Fig. 39.16. Blood flow signals isolated
from ipsilateral corpus luteum demonstrate
a moderate to high resistance index
(RI =0.54)