We have seen some very appealing ads from vendors, aimed at the public. Ultrasound manufacturers are doing what the drug companies have been doing: advertising to the public, with the intent of getting patients to influence what doctors prescribe, and now, which ultrasound machines they will buy and use.
There is no question that 3D and 4D ultrasound is the wave of the future, and some day, many ultrasound departments will have machines capable of performing 3D or 4D ultrasound.
3D and 4D machines have advantages in evaluating abnormalities of the uterus, ovaries, and the fetus.
3D and 4D does provide outstanding images for the parents and family and provides outstanding “bonding” of the mother and father to the unborn child. Many feel this is important.
3D gives us a 3 dimensional image of whatever we are scanning. With a machine that can give 3D imaging, the transducer takes a series of images, thin slices, of the subject, and the computer processes these images and presents them as a 3 dimensional image. Using computer controls, the operator can manipulate the image and obtain views that might not be available using ordinary 2 dimensional sonography (2D).
In the 3D machine, the series of images is called a volume. After the volumes are obtained, the computer has to have time to work on these volumes, like a huge math project.
There are different kinds of 3D. For example, some machines require that the operator move the transducer over the area of interest by hand to capture the volume. This is not ideal because it takes a good deal of skill and practice to move the transducer perfectly steadily at the proper rate, angle, etc.
Other systems have a motor built into the transducer so all the operator has to do is hold the transducer steady and still, and the internal workings of the transducer will move at just the correct speed to capture a volume. This is better than doing it by hand.
Patients, of course, are anxious to see cute pictures and video of the baby. All of this is done with the understanding that we should keep the exposure of the fetus to ultrasound As Low As Reasonably Achievable (we call that the ALARA principle).