Discussion
To the best of our knowledge, this is the first case of detection of
CPAF with PA/VSD using fetal echocardiography. We present the ECG-gated
CT images which confirmed the accuracy of prenatal fetal
echocardiography and provided much information that would be useful for
surgical treatment. Currently, the evaluation of coronary and pulmonary
artery anomalies is essential for surgical planning in patients with
PA/VSD. Therefore, high-resolution images of fetal echocardiography and
CT play pivotal roles in strategizing therapy after birth. Because
prenatal diagnosis of coronary artery anomalies without coronary artery
dilation is difficult by fetal echocardiography [3], reports of CPAF
with PA/VSD in the fetus are unavailable. It is challenging for
sonographers to detect CPAF because its blood flow is too small or with
low velocity. For this reason, it may be necessary to control the
velocity scale or pulse repetition frequency to diagnose CPAF in the
fetus. Furthermore, CT can be used to identify coronary artery anatomy
in neonates compared with a significantly higher diagnostic accuracy
than TTE and angiography. It provides not only the origin and course of
the coronary arteries but also their relationships with the surrounding
cardiovascular anatomy [4]. However, a previous study on younger
children with lower body weight demonstrated images of the lower
resolution of the coronary arteries by CT [5]. In our case,
retrospective scanning by a 3-cardiac cycle was performed to visualize
the relationship between the coronary artery, CPAF, and mPA at the best
motion-free phase, despite the low body weight. In conclusion, careful
fetal echocardiography can demonstrate CPAF and the ECG-gated 320-row CT
can be a powerful and less-invasive diagnostic modality to make a
definitive diagnosis. The accuracy of prenatal diagnosis using fetal
echocardiography benefits perinatal counseling and decision-making
during planning of therapeutic strategy after birth.