3D Ultrasonography: 3D ultrasound is a medical ultrasound technique, often used in fetal, cardiac, trans-rectal, and intra-vascular applications. 3D ultrasound refers specifically to the volume rendering of ultrasound data and is also referred to as 4D (3-spatial dimensions plus 1-time dimension) when it involves a series of 3D volumes collected over time
4D Ultrasonography: 4D scans show moving 3D images of your baby, with time being the fourth dimension It's natural to be excited by the prospect of your first scan.
What's different is that 3D ultrasounds create a three-dimensional image of your baby, while 4D ultrasounds create a live video effect, like a movie. You can watch your baby smile or yawn. Parents often want 3D and 4D ultrasounds. They let you see your baby's face for the first time.
A 3D ultrasound is performed like any other ultrasound. First, the doctor or technician will rub the gel on your belly and then move a transducer across the area. The transducer directs the sound waves toward your uterus and the baby inside it, giving you a picture of your developing baby.