Imaging technology has progressed to levels unimaginable to physicians who first used X-rays after German professor Wilhelm Conrad Roentgen made his discovery in 1895.
With the advent of each modern imaging technique –computed tomography, magnetic resonance imaging, ultrasound and digital imaging– today’s health care providers have access to increasingly accurate images with which to screen, diagnose and guide them when treating patients.
Mammography might be the best known of the technologies. Long a standard in women’s healthcare, millions of women the world over have had this screening that can detect a cancerous growth in the early stages or before it begins to spread.
At Bexar Imaging in San Antonio, Texas, we have a system to provide 3D or wide-angle digital breast tomosynthesis mammograms with a 50-degree tomographic sweep, which produces more images than the 15-degree to 20-degree equipment on the market.
Xeromammography, which produced a xeroradiographic image of the breast and chest wall on paper instead of film, became available in the early 1970s. We had plates that made an exposure with blue dye. It was an improvement – you could see masses, but they had to be pretty big, and often by that time the cancer was more advanced. It also exposed the breast to more radiation. At the time, however, it was state-of-the-art.
When dedicated mammography units came along in the late 1970s, and early ’80s, the compression of the breast was done manually. We’d use a hand crank to control the compression plate to squeeze the breast as tight as we could. As you can imagine, this technique resulted in compression that was inconsistent from one technologist to another and from one mammogram to the next.
The advent of automated compression created consistency, and by the early 1990s, mammography became more effective, with better image quality and, by the late 1990s, digital imaging became available.
We could now do a mammogram and see a mass, and the radiologist or surgeon could perform core biopsy targeting the mass or perform wire localization to insert a hooked wire into the mass in the breast, either by stereotactic mammography or ultrasound-guided localization. The patient would then be sent for surgical biopsy.
Modern mammography has made it possible for health care providers to detect and treat cancerous masses earlier, with less exposure to radiation than before. At the same time, though, clearer images have slightly increased the chance of false positives and callbacks for repeat mammography.
Digital breast tomosynthesis, or 3Dmammography, one of the newest screening and diagnostic t e c h n o l o g i e s , strives to reduce such incidences and also provide improved imaging of breasts composed of dense fibroglandular tissue.
With 2D mammography, X-rays of the breast are taken on two planes, cranio-caudad (or from top to bottom of the breast) and mediolateral oblique (or side to side), producing two static images.
With tomosynthesis, multiple images at multiple angles are captured as the X-ray scans the compressed breast tissue, producing a series of 25 images that can be read image by image, or as a single, well-defined 3Dimage. This makes it possible for a radiologist to see enhanced definition of masses and better identify speculation or lobulation.
As mammographers, our most important job is to provide physicians and surgeons with the most accurate information possible to assist them in making an informed decision about whether to biopsy or not. Breast tomosynthesis enables us to detect breast cancers in situ, or while the cancer is still contained within the duct and has not spread outside of the walls and invading other areas of the breast tissue and lymphatic system. Our goal is to find the cancer as early as possible and save lives.
When cancer is detected at this stage, cure rates are in the range of 98 to 100 percent, indicating that women with DCIS are at very little risk of dying from cancer recurrence. Treatment is usually lumpectomy and possible radiation, with or without chemotherapy.