Cancer inside dense breasts can be spotted with the help of a radioactive tracer. This might be the most important test against mammograms, as doctors stated on Wednesday. This new test will also reveal more tumors and will give fewer false alarms, as it is built to be more certain.

The molecular breast imaging will be made with the help of the MBI machine. Being only an experimental method, this won’t replace mammograms for the women at the average risk of the disease. Still, the MBI might become such as an additional tool to discover breast cancer easier.

The MBI might be useful for the women who have a denser breast tissue and whose disease can’t be spotted with the help of the mammograms. This test can be done at a fewer cost than the MRI (magnetic resonance imagining). At least one-fourth of the women who are older than 40 have a dense breast tissue.

Carrie Hruska, a biomedical engineer at the Mayo Clinic in Rochester, Minn., said that the "MBI is a promising technology" that is already in advanced testing. The result will be presented this week at an American Society of Clinical Oncology conference in Washington.

The difference between the mammograms and the MBI is that the MBI uses the radiation in a different way that the mammograms do it, even if the first ones have been the main way to discover breast cancer.

For the MBI, the women are given a shot of a short-acting tracer that is absorbed more by the abnormal cells than the healthy ones. Some special cameras collect the sparkling light that these cells make and so the tumors are discovered.

Hruska said that they were just beginning “to see what this technology can do.”