In the early 1970''s scientists at Washington University made history by developing positron emission tomography or PET scans. The technology revolutionized the diagnosis of cancer. Now, almost 30 years later, Washington University and Barnes-Jewish Hospital are making medical news again by unveiling the first machine in Missouri that combines PET with C-T scans.

"What I''m going to have you do is lie down here with your head here feet down here."

This patient is among the first in the country to have a scan that promises to change the way doctors get images of cancer in the body. For years, positron emission tomography, or PET scans have been used to get pictures of tumors. So have C-T scans or computer tomography images. But this machine at the Siteman Cancer Center marries the two technologies for the first time. It''s called the PET/CT.

"In the year 2000, CT/PET was labeled by Time Magazine the Invention of the Year," says Dr. Barry Siegel, Barnes-Jewish Hospital''s Nuclear Radiologist-in-Chief.

And a dramatic change compared to what doctors have been working with up until now.

"Before we had them in a single device. A patient would have a CT scan as one study, a PET scan as another study and we had to put together in our brains. Now the computer does that for us," says Dr. Siegel.

The result is this amazing reproduction of not only human anatomy, but the cancer that lies within.

"The CT images are shown as the gray scale images that show the anatomy. The PET images are in color and the orange we see in the area I''m pointing to right now represents a lung cancer."

Here''s how the new machine does it. First, the scanner gathers the CT image in just 30 seconds. Then the machine switches to the PET mode. For patients it means just one test where they have to lie still instead of two.

There''s another benefit for patients. Doctors say not only do they create a better scan, they can do it in less than half the time than the traditional image. That means instead of an hour, scanning time takes only about 20 minutes.

"I think its primarily an advantage in terms of their comfort because lying still for an hour is hard for almost all patients so getting the exam done more quickly is helpful," says Dr. Siegel.

"When I first started, the cat scan I had initially was a lot longer than I have today."

Carolyn Gollub was diagnosed with breast cancer in 1996. She knows the anxiety and boredom of enduring diagnostic tests.

"It''s a long time and it''s exhausting and I''m used to it now so this will be a wonderful breakthrough," says Gollub.

She is heartened by what she calls this evolution of technology.

"With cancer we make these little baby steps and if we could find a cure that would be amazing."

Short of a cure, doctors say this technology helps make cancer treatment more accurate than ever before.

Dr. Siegel says be believes this new scan will become the diagnostic tool of choice for cancer patients in the years to come.