This retrospective study was designed to evaluate individual sonographic parameters
that might help differentiate congenital diaphragmatic hernia (CDH) from other noncardiac
thoracic masses such as cystic adenomatoid malformation of the lung (CAML) and congenital
lobar emphysema (CLE) prenatally. Twenty-four cases of CDH, CAML, and CLE detected
during prenatal ultrasound and documented postnatally (with surgical, autopsy, or
radiological proof) were identified through extensive chart and record review. The
hard copy gray-scale images were retrospectively reviewed for imaging characteristics
that may differentiate the three entities. Additionally, the prospective diagnosis
during prenatal ultrasound was also compared with the postnatal diagnosis. The most
reliable indicators in our retrospective review included confident visualization of
a diaphragmatic defect (92.3/100.0 PPV/NPV, p ≤ 0.002) and/or localization of the stomach within the chest as well as the presence
of severe cardiac deviation (both 92.3/62.5 PPV/NPV, p ≤ 0.01). Other sonographic indicators (including the presence of cystic areas, side
and size of the lesion and the presence of polyhydramnios) offered lower levels of
sensitivity and specificity. Prospective diagnosis during real-time assessment was
also integral, offering > 80% sensitivity and specificity (p ≤ 0.001). Accurate prenatal diagnosis of CDH is difficult despite the relative frequency
of this lesion. The classic triad of a thoracic mass accompanying a displaced heart,
absence of a normally positioned fluid-filled stomach and polyhydramnios, although
seen with CDH, may not adequately differentiate this entity from other noncardiac
fetal thoracic masses. Realtime assessment remains integral to the appropriate diagnosis.
Pregnancy, ultrasound - fetus, abnormalities - fetus, ultrasound - fetus, respiratory
system - diaphragmatic hernia - pregnancy - hernia, diaphragmatic/pathology - prenatal
diagnosis - fetal diseases/ultrasonography - cystic adenomatoid malformation of lung,
congenital/ultrasonography - ultrasonography, prenatal - pregnancy
