Because mammography does not detect all cancers, researchers are studying other ways to screen women. New methods being evaluated include magnetic resonance imaging (MRI), digital mammography, computer-aided diagnosis, and computed tomography laser mammography (CTLM).
MRI uses magnetization and radio waves, instead of x-rays, to produce detailed images. This test does detect some abnormalities not seen on a mammogram. However, it is less accurate than routine mammography in determining whether the abnormal areas are cancerous. Researchers are continuing to refine technology for breast MRI.
Digital mammography differs from the standard technique in the way the image is recorded, viewed by the doctor, and stored. Standard images are recorded on large sheets of photographic film; digital images are captured electronically and viewed on a computer monitor, allowing radiologists to manipulate the images and, hopefully, miss fewer cancers. A one-and-a-half year trial showed digital mammography to be at least as accurate as standard films, and prompted the FDA to approve the technique early in 2000. Many experts believe it will eventually become the preferred method for breast cancer screening.
Computer-aided diagnosis harnesses computers in the search for abnormal areas on a mammogram. The program analyzes a digitized version of the mammogram, then displays the image on a video screen, with markers pointing to areas it "thinks" the radiologist should check especially closely. Preliminary tests have shown that the system can locate cancers that a doctor would find. However, critics are concerned that the technique may lead to unnecessary biopsies by falsely identifying benign abnormalities as suspected cancers. The FDA has already approved one of these systems.
CTLM uses laser technology to produce a three-dimensional image of the breast that radiologists can manipulate on their computer screens. The scans are done easily and cause no discomfort. However, CTLM is still under evaluation in clinical trials, and is not yet available for general use.
