الفهرس 
Introduction .Only 14 pages are availabe for public view
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Abstract
n Egypt, infant mortality rate due to congenital anomalies is about
15% of all infant death and also leading to elevated morbidity in the
neonatal period.
One of the most consistently used justifications for the use of
obstetric ultrasound is that, accurate diagnosis of fetal malformations
before delivery can provide health care providers and parents a number of
management options.
In second trimester, a large number of fetal head and neck
malformations are detectable by conventional 2D US. However, this
technology can only provide two dimensional sectional views of the fetus,
while individual sectional planes of the region of interest cannot be
achieved in the presence of an unfavorable position of the fetus. Three
dimensional US allows the sonographer to evaluate complex anomalies in
multiple planes, and to store data for post-processing possibilities
However, there is no doubt that an experienced examiner can readily
place together two dimensional planes to create a three dimensional
mental image of fetal malformation.
Our study was conducted, at first, on fifty pregnant females during
the second trimester of pregnancy with 2D suggestion of head and neck
congenital anomalies.
Each patient included in the study was subjected to:
Full history taking.
Thorough clinical examination.
Ultrasound examination, including:
o Traditional 2D ultrasound scans for all cases at private center
with suspected fetal head & neck congenital anomalies.
o Three Dimensional and Four Dimensional ultrasound scan for
cases with 2D suggestion of fetal head and neck congenital
anomalies.
Unfortunately we lost nine cases on follow up, so this study was
conducted actually on forty one pregnant females, including forty two
anomalies.
Out of the 42 anomalies in our study, 3D/4D US was found to be
advantageous in demonstrating fetal anomalies 6 cases (14.3 %) and
equivalent to 2D ultrasound in 31 cases (73.8%), but 3D/4D US was
found to be disadvantageous in 5 cases (11.9%). All the five less
informative cases demonstrated by 3D/4D US was CNS anomalies.
Out of the 42 fetal anomalies, CNS comprised 31 cases, in which
24 showed equal scoring between 2D & 3D/4D US. 3D/4D US was
disadvantageous in 2 cases of ventriculomegaly and 3 cases of posterior
fossa abnormalities (2 Dandy Walker Spectrum & 1 Mega Cisterna
Magna). While, 3D/4D was advantageous in two cases only (1Corpus
Callosum dysgenesis & 1 Cephalocele).
Out of the 42 fetal anomalies, face & neck comprised 11 cases,
there were equal findings between both modalities in 7 anomalies (6
cystic hygroma & one case cleft lip), with additional findings, and image
clarity in 4 anomalies (3 cleft lip and/or palate & 1 cyclopia).
There was statistical significance in evaluation of CNS anomalies
compared to the face & neck anomalies by 2D US, as our study
demonstrated the lack of confidence in detection of facial anomalies by 2D US in comparison with CNS anomalies. Yet, no statistical
significance was found by comparing findings by 3D/4D US.
In our study, as diagnoses were only made after the completion of
both 2D and 3D/4D imaging, we were unable to compare the
performance of 2D US alone versus 3D / 4D US assessment. Some
aspects that have served as limitations to this study include small sample
size and lack of diversity of anomalies, especially in the facial region.
Large studies comparing the diagnostic performance of 2D US and
3D/4D US for the diagnosis of congenital anomalies have shown
discordant results. A definitive answer to this question remains elusive as
small numbers, varying patient populations, and different outcome
measures limit these investigations.
According to our findings, 3D/4D US has shown some advantages
and more live clear image over 2DUS in demonstrating certain anomalies
of the face, especially cleft palate and intracranial midline structures as
well as spinal column. The level of diagnostic confidence by 3D/4D US
was increased in many other cases, even if eventual outcome was not
changed.
3D/4D US has tremendous techniques to measure and estimate
different fetal anatomical dimensions, for example, the tentorovermian
angle in diagnosis of posterior fossa abnormalities, jaw index to assess
mandibular size or inferior facial angle to assess fetal profile.
Nonetheless, all this techniques are complicated, require expertise, and
one must keep in mind the various artifacts that may be introduced and
that might ultimately lead to false diagnoses or reassurances.
There are still some problems like surface rendering in
oligohydramnios and movement artifacts during volume acquisition that
need to be resolved.
We concluded that 2D US remains the gold standard in assessment
of fetal anomalies, and 3D/4D US, therefore, is not a screening technique
but an adjunct to 2D US for those fetuses in whom malformations are
already determined or suspected on the basis of standard sonography.