All ultraosunds or sonograms use sound waves to create an image. 2D ultrasound is the most common form of ultrasound. 2D means “2 dimensional”. It is the traditional black and white modality common in pregnancy sonograms. What is commonly misunderstood is that 2D ultrasound is the primary modality for all 3D ultrasounds and 4D ultrasounds through a collection of 2D images. There would be no 3D/4D ultrasound without the 2D ultrasound modality. 2D ultrasound was first used in clinical applications starting in 1956 by a Obstetrician named Ian Donald. Needless to say, ultrasound has been around a long time because of it’s safe characteristics and has earned the reputation of being a preferred modality in many medical imaging procedures.