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.