But whether breast X-rays provide benefits to women between 40 and 50 is murkier.

Yet under 15 percent of women over 50 have ever had a breast X-ray.

Even so, officials say that by improving the quality of breast X-rays, they have increased the accuracy of mammography over all.

For many years, breast X-rays were largely used as a diagnostic tool to help identify possible tumors discovered in physical exams.

The actual breast X-rays are even more loosely scrutinized.

He handed radiologists a stack of breast X-rays and asked them to spot the cancers.

The vast majority of doctors reading breast X-rays are general radiologists who at most took a medical school rotation in mammography.

It soon became clear that the same system could be used to 'read' breast X-rays and uncover the earliest signs of disease.

The federal government advocated the breast X-ray like no other medical procedure.

Some cysts can only be seen on a mammogram (breast X-ray) or with ultrasound.