Computer scientists at Brigham Young University have created a "virtual surgery" tool that lets surgeons, diagnosticians and others extract a 3-D computer image from medical scans.

The software, Live Surface, could be valuable for preoperative exams, diagnosis and evaluation — and for showing patients and their loved ones medical information in a form they can understand, said William S. Barrett, a BYU professor who, with graduate student Chris Armstrong, developed the software.

It might even have the potential to eliminate some exploratory surgeries, said Barrett, although "the proof is in the pudding, and we don't know that quite yet."

The program lets surgeons visualize any part of a patient's anatomy by extracting a 3-D computer image from MRI and CT scans or similar data. But doctors aren't the only ones who may find the program useful, said Barrett. The software also can be used to extract a single actor's performance or inanimate objects from video clips.

The 3-D rendering of anatomy is not what's new about the software. Nice renderings of anatomy have been around for years.

But the tools in the software allow doctors and others to arrive very quickly at anatomical images that in the past "took a fair amount of heroic effort," Barrett said. The new program provides "segmented tools that have been lacking."

A computer program, in processing a photographic image, doesn't know people or cats or birds or dirt roads, Barrett explained. When it looks at the picture, "it says there are a lot of ways this could be divided up."

The program, however, uses an algorithm that lets the computer do the "heavy lifting" of bringing out the image in a simple, interactive and very fast process that requires only minimal input from the user.

Barrett credits recent breakthroughs in algorithms that allow the program to work in a kind of paint-by- number fashion, extracting objects from coarse to increasingly refined levels. As for fast, he said, "we're able to traverse 10-15 levels of the hierarchy in less than a half-second."

It's as simple as telling the program, "This is the object I want," and "I don't want that."

Most of the programs that let doctors look at patient anatomy are either too basic or take too long to be useful. Live Surface is interactive and fast, Barrett said. And it lets a physician isolate tricky anatomy such as soft tissue, including blood vessels, hearts and muscles.