While no one looks forward to a mammogram, they're a fact of life for women. Mammograms are a form of-x-ray used specifically to view breast tissue; they've been used for screening since the mid-1960s. Breast cancer is second only to lung cancer in claiming women's lives, so mammograms have become crucial diagnostic tools.
But there have been questions about their safety and effectiveness in some situations. The radiation used in an annual mammogram is less than it used to be, but it's still more than from a chest x-ray. Because mammograms are still a relatively new technology, the possible dangers of regular mammograms over the course of a woman's lifetime still aren't known.
There is another type of breast cancer screening available, however, and it's been around for a long time.
Digital infrared thermal imaging (DITI), or thermography, is another medical diagnostic tool. It's similar to infrared devices that monitor nighttime movement, used by military troops as early as the 1950s. The technology is based on the principle that bodies radiate heat through skin. Variations in temperature are visible as a change in color, providing valuable images for breast exams and other types of health screening.
Thermography and mammography are different and intended for different purposes. Mammograms show the structure of forming tumors. Thermograms provide information about changes in the body, or the body's physiology, that will support the growth of a tumor.
Before a tumor has a large enough structure to be visible on a mammogram, it's forming, being fed by the blood supply. That blood flow has a temperature, and corresponding color, that will show up on a thermogram. A trained thermographic technician will view it as "suspicious." A follow-up mammogram can then provide the structural information to show whether the area is, in fact, a tumor; a biopsy will determine if it's cancerous.
Madison physician Stanger recommends thermal images be done three months apart for initial breast screening. "The initial image may show color patterns that are not symmetrical, but normal for that person. If there are no changes in the color patterns seen on the follow-up image, then the individual's baseline normal images have been established for future comparisons." After the baseline's been established, yearly thermograms can be performed to check for changes in the color pattern that "could be the start of pathology, like an early cancer," says Stanger. While mammography will detect about 80%-90% of breast cancers in women without symptoms, according to the American Cancer Society, mammograms do have their flaws. Testing is more accurate in postmenopausal women than in premenopausal women; breast density and inadequate positioning of the breast can obscure tumors, and small, early signs of an abnormality are hard to see. These shortcomings with mammography get to the heart of why thermography can be a good choice for many women. Premenopausal women, ages 30-52, "typically have denser breast tissue, because the tissue is still hormonally active," Stanger explains. The breast tissue may be abnormal, but it may take years for a lump to develop that can be seen through radiation. Because tumors grow quicker in younger women, and increased levels of radiation are often needed to image their denser breasts, early detection is essential. Thermography can be used as an initial screening tool, avoiding ionizing radiation that might otherwise be used to image premenopausal breasts. It's important to remember that breast cancer can only be diagnosed by a tissue biopsy, but thermography provides vital information that can help detect signs that the body is forming a tumor earlier than a physical exam or a mammogram. Thermography is also beneficial for postmenopausal women. Stanger was initially drawn to thermography to monitor any changes in breast tissue in her patients using bio-identical hormone replacement therapy. "So far, I've not had a case where the baseline changed in response to hormone therapy, but I remain cautious. For safety, I include thermographic screening as part of the treatment plan." Thermography is done with a camera that does not require radiation or direct contact, so it's safe to repeat as often as necessary, pain-free and suitable for all sizes of breasts, including breasts with implants and men's breasts. Pregnant and lactating women are advised not to get x-rays, but thermography is a safe diagnostic tool for this population. Curious about my own images, I scheduled a breast screening with Tina Perry, Dr. Stanger's assistant and thermographic technician. I was asked to undress from the waist up and put on a medical gown. When Perry returned, I sat on a rotating stool, with the camera an arm's length away. Six images were taken of my fully exposed breasts with my hands behind my head - front, side and back views (the back shows lymphatic tissue). The session was over in less than five minutes. Afterward, I had a chance to take a quick look at the colorful images on the computer. The breast area was mostly green and blue, but there were shades of yellow, orange and red in other areas - the brightest red was in the armpits. Perry mentioned that blue-to-black areas show the coolest temperature and white-to-red are the hottest; inflammation will show up as red or white. Since breast tissue is located away from the body, healthy tissue has cooler colors. She's been trained to adjust the machine to show the best color scale for each individual, to compensate for the fact that different bodies have different baseline temperatures. I knew I would need to schedule a second thermogram in three months to determine my unique baseline thermal "fingerprint," but noticed cool colors and symmetry in the image and hoped that was a good sign. As a companion to mammography, thermography shows great potential for early diagnosis and preventative treatment. If areas show up as suspicious but cannot be seen on a mammogram, less invasive forms of treatment, such as lifestyle changes, might be possible. Thermography also offers hope in more accurate diagnosis of chronic, undiagnosed conditions. "Thermography allows us to see the roots of our pain and underlying seeds of manifesting disease," says Stanger. "It's great for imaging certain kinds of pain and inflammation." (It is not a helpful scan for most types of cancer besides breast cancer.) Dental abscesses will show up, and the scan is also great for pinpointing the exact location of sports injuries or other vague pain. Stanger has also seen changes associated with very early diabetes when imaging the hands and arms. Given the safety of thermography and its potential as an early diagnostic tool, why hasn't it been used more often in conjunction with mammograms? Extensive studies with over 300,000 women, including long-term studies, were done for over 30 years before the FDA approved thermography in 1982. Stanger mentions a study from the 1980s with results that she feels were misconstrued: "Images were taken of subjects with both mammograms and thermograms. Many more abnormalities were seen on the thermograms than on the mammograms, and the images were considered 'false positives.' But you can't compare thermograms and mammograms, because they measure different things in the body."