The difference between 4D ultrasound and 5D ultrasound differs in time and principle. Four-dimensional color ultrasound: mainly using the principle of three-dimensional imaging. To clearly observe whether the various organs of the child are abnormal. The best examination time is 20-24 weeks of pregnancy. Four-dimensional color ultrasound is more widely used than five-dimensional color ultrasound. The best time for 5D ultrasound is between 24-26 weeks of pregnancy. During the examination process of 5D color ultrasound, it can present a 360-degree three-dimensional presentation of the development of the fetus in the uterus, with super high clarity and resolution, which is higher than that of 4D color ultrasound, and the scope of diagnosis will be more comprehensive. Four-dimensional and five-dimensional ultrasound are both methods of obstetric examination to help understand the growth and development of the fetus. If you need to do color ultrasound examination, you need to go to the regular medical institutions.