Thermography: Procedure, Benefits & Risks

One of the best imaging methods currently being used in the medical sector is thermography. This method is used to assess the temperature of various areas of the body. Increased metabolism due to inflammatory pathologies or muscle spasms can lead to high body temperatures ^[1] . Areas where there is poor localized blood circulation display lower temperature. Thermography involves the usage of a camera where a higher temperature is shown in brighter colours whereas colder areas are denoted by darker colours.

Read on to know more about how thermography serves to be a great risk assessment tool, its working methodology and its effectiveness.

What Is Thermography?

Thermography (also called thermal imaging) is a test that makes use of an infrared camera to capture and hence detect heat patterns and the flow of blood in the bodily tissues. Diagnosing breast cancer has become easy with the help of digital infrared thermal imaging (DITI) ^[2] . This technique of breast cancer diagnosis works by revealing temperature differences on the surface of the breasts. The idea followed is that since cancer cells multiply, they would need more oxygen-rich blood to grow. So, when the tumour begins to receive more blood flow towards it, the temperature around it rises.

Thermography (also called infrared thermography) enables doctors to track thermal (heat) patterns throughout the patient's body with the use of ultra-sensitive, high-resolution digital infrared cameras. The thermography procedure takes about 15 to 30 minutes. It does not involve compression, contact or radiation.

Thermography has also been used by doctors to predict if any other part of the body is inflamed or shows signs of abnormality.

How Thermography Works

Thermography involves the use of cameras that detect heat naturally emitted from the human body. The results obtained after the test is known as thermograms ^[3] . Infrared thermography involves converting infrared energy into an image that is visible. It needs to be understood that the amount of radiation emitted increases with temperature. Thermography tests are able to track variations in the body temperature (between two different people). It can also track changes in the same person's surface temperature over time ^[4] . However, note that heat radiating from the human body is not the same thing as dealing with radiation therapy.

Use Of Thermography

Although extensively researched for its role in detecting breast cancer, thermography imaging can also be used to track changes in the following cases ^[5] :

• Fibrocystic conditions in women
• Presence of infections
• Existing allergies
• Cardiovascular diseases affecting the arteries

In general, thermograms can be used to evaluate sensory-nerve irritation or significant soft-tissue injuries. They can also be used to identify pain sources.

Thermal imaging cameras have also found usage in other walks of life such as the following ^[6] :

• In airports to detect illnesses (such as swine flu) or concealed weapons
• By firefighters to detect smoke and to find civilians who might have been trapped
• By military personnel as a part of their surveillance protocol

Compared to self-examinations, thermography tests are reliable as they can detect abnormal cellular activities and suspected tumour growths at an early stage.

Who Should Get A Thermogram?

Many researchers have promoted the fact that thermography serves to be the best and most effective screening test for women under 50 and also for women with dense breasts ^[7] . Mammograms fail to be as sensitive as thermograms in these two mentioned groups. Nevertheless, experts always say that thermography should not be a substitute for mammography as it sometimes fails to pick up breast cancer on its own. According to the recommendation of the FDA, women should use thermography as an add-on test alongside mammography ^[8] .

What To Expect During The Thermography Procedure

A person should avoid wearing deodorant on the day of the thermography test. The person is usually made to undress from the waist up for sometime before the test begins. This is to make the body acclimated to the room's temperature. The person is then made to stand in front of the imaging system. About a series of six images (including front and side views) of the breasts is taken by a technician ^[9] . The entire test should not take longer than 30 minutes. You will be provided with the results within a few days along with a test analysis from your doctor.

Possible Side Effects And Risks Of Thermography

It should be noted that the FDA has not cleared thermography as an alternative to mammography and hence it should not be used as a replacement for breast cancer screening.
There are no real risks associated with thermography as there is no radiation exposure and no compression of the breasts ^[10] .

In spite of being safe, there is no clinical proof that regards its effectiveness. With cases of high false-positives and not being as sensitive as mammography, many medical experts do not advise its use for screening and diagnosing purposes.

The Downside Of Thermography

When compared to mammography (which uses low-dose X-rays to take pictures from inside the breasts) ^[11] , thermography is considered quite beneficial as it does not give off radiation and is non-invasive as well. However, based on a few studies it can also be said that thermography is not as effective as mammography at detecting breast cancer.

Although considered far less sensitive than mammography, thermography has also shown a high rate of false-positives (finds cancerous cells when there aren't any present) ^[12] . Hence, some medical experts term that it is not reliable completely. The problem with thermography is its ability to distinguish between the causes of increased heat. Signalling warmth in the breast can indicate breast cancer but it can also indicate noncancerous diseases such as mastitis. Although mammography also has had instances of false-positives, it still is considered the most effective method for diagnosing breast cancer, especially in the early stages.

Preparing For Thermography

Before you get a thermal imaging test done, you will need to ensure the following ^[13] :

• Do not eat anything too hot or too cold for at least 2 hours before the test.
• Avoid smoking at least 2 hours before the test.
• Avoid getting a massage or attending physical therapy on the day of the test.
• Do not use products such as perfumes, deodorants, lotions, powder, etc.
• Wear loose clothing.
• Do not exercise 2 hours before and 2 hours post the test.
• Do not have the test if you have a sunburn on your skin (avoid going out in the sun following the test).

On A Final Note...

Although not intended to treat cancer cases, thermography tests serve to be one of the best methods that can be incorporated as a part of early risk assessment programs for breast cancer. Thermography is capable of identifying patients who are at high risk of cancer and hence pave the path for an increase in the effective use of mammography. Moreover, one noteworthy feature is that thermography can be performed years before conventional mammograms are ordered. This assists the doctors in identifying patients who are at high risk for cancer development and thus can be monitored more carefully.