The diagnostic purpose of 4D ultrasound: 1, prenatal screening of teratology is the main focus, including screening of various fetal systems and organs, including a fetal heart screening. 2, about the heart screening: through the fetal heart structure (heart position, left and right ventricular outflow tract, the continuity of the septum, four-chambered heart structure, etc.), can detect about 80% of fetal precordial disease. 3.Does the 4D have to be responsible for taking pictures? Answer: No, 4D is understood by the majority of patients to be responsible for taking pictures, in fact, the 3D presentation of the fetus is very simple, but it is limited by the amount of amniotic fluid in front of the fetus and the position of the fetus, so not all fetuses can be presented. The purpose of ultrasound is mainly to detect malformations, not to entertain.