One out of every two women in America over age 45 has osteoporosis. And 75-percent of them have yet to be diagnosed.

DR. DON STROMQUIST/RHEUMATOLOGIST: "I THINK THE DIFFICULTY IS IT DOESN'T SHOW ITSELF UNTIL A CATASTROPHE HAPPENS, WHICH USUALLY MEANS BREAKING A BONE."

Dr. Don Stromquist specializes in the treatment of bone disease. While x-rays help show where a bone is fractured, Dr. Stromquist says normal x-rays can't detect missing bone mass until 25..maybe 50-percent... of it is already gone.

Q:"WHICH IS WHEN IT'S TOO LATE?" A:"WAY TOO LATE."

This is where the dual energy x-ray absorptiometer-- otherwise known as DEXA-- comes in.

ANGELA AN/EYEWITNESS NEWS: "COMPARED TO OTHER X-RAYS, THE DEXA CAN DETECT BONE LOSS AS LITTLE AS ONE-PERCENT. THE MACHINE SIMPLY TAKES A PICTURE OF A MOVINGOF YOUR SPINE AND YOUR HIP... PRODUCES THAT IMAGE ONTO A COMPUTER AND THEN COMPUTES YOUR BONE DENSITY COMPARED TO WOMEN OF THE SAME AGE."

The machine analyzes how much x-ray is absorbed into the bones. Doctors like Stromquist can then precisely measure the bone density year after year, determine what treatment to use, and if it works.

DR. DON STROMQUIST/RHEUMATOLOGIST,: "AND NOW THAT DRUGS ARE AVAILABLE WE CAN INTERVENE AND WE THINK MAKE THEIR FUTURE BETTER."