Introduction
Transvaginal three-dimensional ultrasound (3D-US) has been used widely
in gynecological field ,especially in classification of the uterine
malformations(1,2) and diagnosis of uterine adhesion(3,4), which has
shown satisfactory concordance with other “gold standard”
examinations, such as laparoscopy and hysteroscopy(5,6) and
hysterosalpingography(7). The advantage largely arises from its ability
to reconstruct the coronal plane of the uterus, which allows for
visualization of the outer and inner contour of the uterine walls
yielding accurate measurement of the sub-septation length and cavity
width(8,9,10). To distinguish between normal uterus cavity and Mullerian
duct anomalies or uterine adhesion, a coronal plane would be useful in
demonstrating their distinguishing features. Normal uterus was defined
as any uterus having either straight or curved fundal and interostial
lines but with the internal or external indentation at the fundal
midline not exceeding 50% of the uterine wall thickness(11). Internal
shape of endometrial cavity, uterine contour, fundal indentation, and
septal length can be accurately demonstrated using real-time 3D-US .
Uterine synechiae or adhesions have a significant adverse effect on
fertility. The degree of adhesion can be mild, moderate, or severe
according on whether adhesions involve one-fourth, one-half, or over
three-fourths of the uterine cavity(12). 2D ultrasound may present a
diagnostic clue to adhesions within the endometrial cavity through the
presence of bands seen within the endometrial echo, particularly with
the aid of sonohysterography. However, the true narrowing or “bands”
adherent across the cavity is usually well delineated on the coronal
plane on 3D imaging and 3D-US can predict adhesions and cavity damage
with greater accuracy than hysterosalpingogram(13) and obliteration
(undetectable endometrium) in 3D-US showed 100% sensitivity to diagnose
uterine adhesion(3). According to our experience, shape and area of
uterine cavity in the coronal section of the uterus is very important
information to distinguish between normal uterus cavity and uterine
adhesion(14), just as it plays an important role in evaluating the
endometrial cavity post-septal resection or metroplasty(15). So, We
propose that it is very necessary to determine a “normal” and more
specific uterine cavity using real-time 3D-US measurements in the
coronal view, which could help us to determine the degree of uterine
adhesion, to judge whether a certain intrauterine device is suitable or
not, to calculate the ratio of normal and abnormal uterine cavity in
some gynecological diseases, et al.
The purpose of this study was to evaluate uterine cavity measurements in
adult women of childbearing age who have normal uterine cavity confirmed
by hysteroscopy and to confirm the range of “normal uterine cavity”.
It may be a basic research for the clinical application of uterine
cavity morphological measurements to judge some gynecological diseases.