Quite simply, ultrasound, which is used in many different fields, is sound waves beyond the human hearing range.
Here’s how ultrasound works in pregnancy: As early as 16 weeks, women can see a “fetal portrait” of their baby and determine its gender. Ultrasound technology has improved dramatically over the decades from flat, grainy black and white images to the current three-dimensional time experience.
Most hospitals offer some 3D scanning, but 3D ultrasound produces images that show the width, height and depth of a developing child. Rather than sending sound waves straight into the womb and recording when they bounce back as is common in 2D imaging, 3D ultrasound sends sound waves from different angles. A computer then renders a 3D image based on this data.
4D ultrasound adds movement as it occurs. The fourth dimension is time. You’re actually watching your baby live in 3D mode. How cool is that?