UBC Reports | Vol. 49 | No. 1 | Jan. 2, 2003

3D Ultrasound, Coming Soon to a Doctor Near You?

Improved technology gives doctors a better look inside

By Michelle Cook

Moms-and dads-to-be may soon be able to see their growing babies more clearly thanks to new ultrasound technology. The advanced imaging method could also help medical professionals to improve their diagnostic capabilities in detecting cancer and removing tumours. That is, if they’re willing to make the switch to 3D, says Robert Rohling, a professor of Electrical and Computer Engineering at UBC.

“Three-dimensional ultrasound is slowly making its way into the marketplace, but doctors have to be convinced that it’s useful to them, otherwise they won’t spend the money to buy expensive machinery or spend the time training to use it. They’re tough customers for good reasons, so you have to prove to them it will make a difference in making better diagnoses or interventions,” Rohling says.

3D ultrasound has been used in research labs for almost 15 years, but it is just now beginning to make its way into practice. Rohling’s research focuses on developing better quality 3D-ultrasound technology for clinical use. His efforts were boosted recently by the purchase of a GE 730 Expert. The first equipment of its kind in Western Canada, Rohling calls it the “Porsche” of ultrasound machines.

So, just what difference does 3D make when it comes to taking a peek inside ourselves?

Judging from the image that pops up on the GE 730 of twin fetuses wiggling around in the womb, it’s a lot like the difference between black and white and colour TV.

Rohling prefers to use the analogy of a loaf of bread.

“2D-ultrasound images are flat, grainy-looking and unless you’re a skilled technician, can be hard to decipher,” Rohling says. “2D generates a cross-sectional image which is like looking at a single slice of bread, instead of the whole loaf.”

These images can be difficult to interpret because we live in a three-dimensional world, Rohling explains, and our mind has a
difficult time trying to fit these two-dimensional pieces together into a three-dimensional object.

3D ultrasound also produces cross-sectional slices, but stacks them together into a volume -- like a whole loaf -- that has width and depth and height and can be viewed from multiple angles.

By using computer graphics principles that are “a lot like the ones you’d see in the latest blockbuster movies,” Rohling says 3D ultrasound can also be used to single out individual features, like skin, for examination. The technique is called volume rendering.

Rohling is quick to point out that 3D technology is not meant to replace 2D ultrasound, which is currently used in 99 per cent of ultrasounds worldwide, but to complement it.

From the patient’s point of view, 3D can give them a better understanding and a more concrete connection between what they see on the screen and reality.

While experienced sonographers already do a tremendous amount with 2D images, Rohling, who has a background in biomedical engineering, hopes his research will help doctors to improve on a number of procedures. In the area of diagnoses, he hopes to enhance the clarity and resolution of images so that clinicians can see minor details and detect cancers at earlier stages. In the area of intervention, which includes biopsies and surgery, he is working on providing special ultrasound tools and software to physicians to allow them to perform these faster, easier and more accurately.

He has also been working with a team of researchers nationwide on neurosurgery innovations. Currently, physicians must rely on day-old MRI scans when operating on the brain. The problem is the brain can shift and expand during surgery. Rohling hopes to use a small brain probe to provide surgeons with “real-time” ultrasound updates of the MRI scan during the procedure.

Rohling says it’s difficult to guess when 3D-ultrasound technology will become commonplace, but estimates clinical results will start to appear in a few years. In the meantime, Rohling is using the latest in ultrasound technology on himself.

“I’ve used the GE 730 to look at my abdomen and kidneys and they scanned very well. Everything seems fine,” Rohling laughs.