What is Thermography? 

 August 25, 2022

By  Randy Angwin

Last updated on August 25, 2022

Thermography or thermal imaging creates a thermal image of objects or bodies using a thermal camera. Hero of Alexandria made the first attempt to measure different bodies' heat. Still, the technology was first used by the US military in 1947 and has been used in several applications since then. 

So, what is thermography? How is it used in engineering and medicine? Keep reading to learn more about this technology. 

What is Thermography Used For?

Thermography relies on unique cameras that measure the heat of an object that operates in normal conditions. Using these cameras, operators can detect changes in the heat pattern. 

This technology can be used in engineering and industrial applications, as a diagnostic tool in medicine, and in military applications. 

What is Thermography Used for in Engineering?

Thermography, including thermal imaging and video, uses thermographic cameras to detect radiation in the long-infrared range. Warmer bodies are shown up against a cool background to detect changes in their internal temperature. 

In engineering, thermography is used as a non-destructive testing method to detect several issues. 

  • It can detect air leaks and clogged condenser tubes in cooling systems. 
  • The technology is a security measure to detect corrosions and erosions in industrial plants operating at high temperatures.
  • It’s used to detect faulty thermal insulation in factories. 
  • This technology is used to detect drafts from windows and doors.  
  • It can be used to detect composition changes and disbands in laminates. 
  • It’s used in engineering to inspect electrical and mechanical equipment to obtain heat distribution pictures.

Uses of Thermography in Medicine

In medicine, thermography detects heat patterns in the body as they’re affected by the blood and oxygen flow in several tissues. A particular type of thermography, called Digital infrared thermal imaging, is used as a diagnostic tool to detect thermal changes in the body tissues. 

For example, in the case of cancer, the body cells multiply, and they need more oxygen-filled blood to grow. When the blood reaches the cells, the temperature of the surrounding tissues increases. 

However, thermography isn’t as sensitive as mammography in detecting breast cancer because it has a relatively high false positive rate. So, doctors only use it when some risks prohibit the use of mammography to detect a tumor. 

Passive vs. Active Thermography: What is the Difference?

Two types of thermography can be used for different purposes. 

  • Passive thermography is the technology used in surveillance, military, and medical diagnoses. This technology is based on the concept that the object studied naturally has a higher or lower temperature than the background. 

This technology is popular in industrial applications to detect the weld quality in plastic joints or damage. In addition, passive thermography covers larger areas and allows for non-contact measurement with real-time implementation. However, this type of thermography is restricted to surface level and cannot detect in-depth changes. 

  • Active thermography is used when the temperatures of the object tested, and the background is identical or close to one another. It relies on inducing heat in the test object to change its temperature in a transmissive or reflective setup. 
Unlike passive thermography, which detects surface-level changes, active thermography can detect in-depth changes in layers. This is why it’s usually used to test the quality of welds and inserts in plastics in aerospace and automotive industries, the breakage 

What Diseases Can Thermography Detect?

Thermography can successfully detect diseases by identifying areas of inflammation, even before the patient suffers from any symptoms. Then, any changes can be further investigated or recommended for a follow-up to prevent an early health condition from worsening. 

This technology is used as an early testing or screening tool, but it’s not always conclusive, so it should be used with another testing or screening tool to confirm the disease. Using thermography testing, doctors can detect several diseases at early stages with the help of a digital infrared camera that draws a map of the body’s temperature pattern to see any changes or unusual patterns. 

This body map usually highlights areas of inflammation in the body, indicating something wrong. Here are some diseases that doctors can detect using thermography. 

  • A cardiovascular disease that leads to skin temperature changes. 
  • Diabetes.
  • Thyroid issues.
  • Metabolic disorders.
  • Hormonal imbalances.
  • Digestive disorders.
  • Allergy and sinus problems.
  • Temporomandibular Joint (TMJ) disorders.
  • Internal inflammation.
  • Carpal Tunnel syndrome. 
  • Nervous system disorders. 
  • Herniated disks.

Can Thermography Detect Cancer?

Thermography can detect cancer but not at the early stages. Once the tumor has increased in size enough to be seen by a thermal digital camera, the inflammation is too severe, and the cancer is already spreading. 

Is Thermography Better than Mammogram?

Mammograms are far better at detecting breast cancer, especially at the early stages. Thermography can produce false positive results, meaning the patient might undergo unnecessary testing. At the same time, the thermography test might skip cancerous cells if they’re still developing at an early stage, affecting the recovery and survival chance of patients

However, a thermogram can test women under 40 or those with dense breast tissue. Since mammograms aren’t sensitive in these two cases, a thermogram can be a helpful diagnostic tool. 

What is the Difference Between a Mammogram and a Thermogram?

A mammogram is an X-ray image of the breast, which can identify tissue types to detect any unusual masses. A thermogram draws a thermal or infrared image of the heat pattern near or on the skin.

Which is Better?

Mammograms are better than thermograms in detecting breast cancer, especially at early stages, and according to the FDA, a thermogram isn’t considered a substitute for a mammogram. Mammography is still the most effective screening and testing tool to detect breast cancer at its most treatable stages. 

Does Insurance Typically Cover Thermograms?

Insurance doesn’t usually cover the cost of thermography, but it covers the cost of mammography. 

Who Should Get a Thermogram?

Women can start thermogram screenings at the early age of 20, unlike mammograms prescribed for older women. The doctor can detect thermal changes and recommend more testing if something looks suspicious. Some women can also choose to have thermograms if they don’t want to be exposed to the radiation used in mammography, although it’s minimal. 

Possible Side Effects and Risks of Thermography

With no radiation or breast tissue compression, there are no side effects or risks of using thermography. However, the only problem is that thermography can lead to false positive results or skip a cancerous tumor still developing in its early stages. 

Final Thoughts

Thermography is a popular technology in industrial, engineering, military, and medical applications. There are two types of thermography; passive and active, and each can be used for various purposes. 

In medicine, although thermography can be used to detect internal inflammation and diagnose several health issues, it’s not recommended to be used as a screening tool for breast cancer. Mammograms are still better at detecting cancer, especially at its early treatable stages. 

About the author 

Randy Angwin

Randy Angwin holds a master of science degree from University of Florida. He is an expert in infrared and night vision technology. His knowledge helps us staying on top of the latest trends in the thermal industry. When not working, Randy likes to hunt and spend time with his two German shepherds.

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