Thermography or Computerized Thermal Imaging
What is thermography?
Thermography is also known as digital infrared imaging or computerized thermal imaging.
To screen for breast cancer, a thermographer blows cool air over the breasts. This causes the amount of blood going to the breast to be reduced.
Sophisticated computer programs allow the doctor to isolate differences in temperature and perform other tests to determine if there is any trace of cancer.
Identifying precancerous conditions
Dr. William Cockburn is a board certification clinical thermographer. He has written extensively on the benefits of this procedure.
He writes that, "...thermography is capable of detecting and measuring the body's physiologic response to abnormality and mammography is capable of detecting and measuring the structural or anatomical lesions present. It has been estimated that thermal imaging is 8-10 years ahead of mammography as a risk indicator."
How does it work?
Cancer cells grow and multiply much faster than healthy cells.
As they grow they build up a network of their own blood vessels. They need the extra nutrition supplied by this network to continue to grow.
Both of these factors cause areas with precancerous or cancerous cells to be hotter than the surrounding tissue.
Thermography is based on this idea. It takes an infrared picture of the breast that shows temperature in various colors. "Hot" spots are areas that identify suspected cancer.
The amazing brain
The human body has many built in survival features controlled by the brain.
One is heat conservation. Blood carries heat to the skin as a way to maintain a constant temperature in our bodies.
When we are exposed to cold, the blood vessels closest to the skin constrict. They get smaller so that the blood will be forced away from the cold and into the core of our body where our most important organs are.
This heat regulation mechanism maintains the warmth the body needs to function.
That's why your fingers and nose get cold when you are out on a chilly day. Your blood has gathered away from the skin to conserve heat and protect you from hypothermia.
The flush you notice when you have a fever or get overheated is the blood rushing to the surface to get rid of excess heat. This is your brain protecting you from hyperthermia.
Cancer cells take control
The network of blood vessels that the cancer cells have created is not under this autonomic control. These blood vessels obey the cancer cells, not the body. They will not respond to the brain's order to shut down to conserve heat.
Since the area where cancer cells are beginning to grow or where the cancer has built its blood vessel network is unaffected by the cool air, it will stand out clearly on a thermographic image as a "hot" spot.
Why is it not used for screening?
In theory thermography sounds perfect. It is non invasive and not painful. It can pick up precancerous conditions and cancer eight to ten years earlier than a mammogram.
Studies have found that this technique can identify cancerous growths. The problem is that it identifies other "hot" spots as cancer too often to be useful as a diagnostic tool.
Cancer is not the only condition that causes "hot" spots. Any slight irritation, infection or hormonal irregularity can cause temperature fluctuations in breast tissue. Thermography has no way to accurately distinguish what is causing a change in temperature in the breast.
Early official findings
The National Institutes of Health Consensus Development Conference Statement issued in 1977 stated, "Because the potential benefits of thermography remain undocumented, the panel recommended that thermography be discontinued as a routine part of the BCDDP [Breast Cancer Detection Demonstration Projects] screening program except in those centers where sufficient expertise is available to justify further clinical investigation and research."
Extensive research has been conducted on thermography since that early advisory.
In 1982, the FDA approved breast thermography as an adjunctive diagnostic breast cancer screening procedure to be used in conjunction with a mammogram. They recommended continued study of the technique.
As of November 2000, the Komen Foundation reported that the Food and Drug Administration (FDA) has reversed its position and at that point did not approve thermography equipment for screening purposes.
The American College of Radiology advised that "thermography has not been demonstrated to have value as a screening, diagnostic, or adjunctive imaging tool."
Return to-> Diagnosing Breast Cancer - Tools & Techniques
Elsewhere on the Web:
What is Breast Thermography
Thermography & Breast Health
Imaginis - Thermography / Computerized Thermal Imaging