Since the early 1960's, infrared thermal imaging has been used in the medical field.  Recent advances in technology have brought the price of infrared thermal imaging cameras down, making this technology more available then ever before.  Medical thermal imaging has been an accepted diagnostic tool in Japan since 1981.

 As all measurements are prone to error, measurements using infrared imaging cannot be perfect.  By making a measurement from a standard meter a physician can make an accurate measurement as close as possible to the true value of the measurement.  A series of measurements cannot be completely precise, however by making measurements as accurate as possible, a physician can achieve a reliable measurement.

Infrared thermal imagers measure the infrared radiation of an object.  As all object emit infrared radiation, knowledge of an object's emissitivity is an essential requirement for the calculation of radiant heat emitted by the object.

There are several factors to consider when measuring the radiant heat of a subject.  Reflections from the environment as well as substances applied on the skin may change the emissitivity factor of the skin.  Additionally hair can block the infrared radiation coming from the skin underneath.  It may take several thermograms of a subject at different times of the day, in order to retrieve accurate measurements.

In order to reduce errors and increase accuracy, standardized positions of the body for image capture and a clear field of view is required.   Variations in body position as well as camera positioning can affect the accuracy of the infrared imaging.

Other factors to consider are the ambient room temperature and pre-imaging.  A range of temperatures from 18° C to 25° C should be attained and the subject allowed to acclimate to the temperature.  Patients should avoid crossing their arms and legs, as contact from body parts can alter the temperature of the skin surface.  

Several other factors to be considered are the influences of cosmetics, alcohol, smoking, caffeine, exercise, and even tight fitting clothes can alter the skin temperatures and thus provide less accurate results.  

Analysis of the infrared images can prove unpractical for an untrained physician.  It is recommended that the a Level I class in thermography be taken in order to better understand how to fully utilize an infrared thermal imaging camera and analyze the results.  Medical Infrared offers thermography classes via our affiliate the Infrared Training Institute. Currently we have plans to offer a specialized medical infrared training course in the near future.

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