Digital infrared thermal imaging (DITI), also known as medical thermal imaging is welcoming a new era. It is a non-contact, non-invasive diagnostic method for study human body temperature. Medical thermography started in 1957 with the discoveries of Dr. Lawson in breast cancer patients. Dr. Lawson found that when using medical thermal imaging, most of his patients with breast cancer had higher skin temperature over the cancer area.
These initial findings showed the potential of medical thermal imaging as part of the diagnostic tools in patients with breast cancer. However, several early problems delayed the acceptance of this technique. One of these was the lack of experience in the usage of the equipment, as the initial equipment was more difficult to use and therefore the results differ from technician to technician. Another of the initial drawbacks was the very low detector sensitivity, which again, contributed to the wide difference in the results obtained. These were the main two reasons that delayed the acceptance of this technique until relatively recently.
Nowadays the modern thermal imaging systems have very advanced thermal cameras, coupled with complete software solutions that can allow recording the images with very high quality for further processing. Therefore, although thermal imaging has been applied in different fields in medical science with proven efficiency before, it has not been until recently that a second, more in deep analysis of its potential uses is being carried in the medical practice. All this advances have contributed to the reborn of medical thermography as a new exciting field full of potential. This is how new and powerful applications with proved results are emerging day by day. One of the most widespread uses of thermal imaging and one where it excels over other methods is mass screening of suspected febrile patients. This was reflected as monitoring the temperature of people in airports and other crowded areas during the recent flu outbreaks. It was widely used in different countries in Asia during the SARS outbreak, and a study conducted in Taiwan proved that the temperature readings obtained by thermal imaging may be used as a proxy for the core temperature of suspected febrile patients. They also concluded in the study that an effective thermal imaging system with a strict operating protocol could be rapidly implemented at the entrance of a hospital during SARS or avian influenza epidemics. This was widely seen during the recent H1N1 influenza pandemic, where monitoring equipment was seen widely distributed at airports, checking for fever as an important symptom for flu and thus preventing further dissemination of the virus. During this pandemic it was very clear the important role that thermal surveillance of thousands of people played in preventing and battling the spread of H1N1 flu.
Medical thermal imaging has been found to be a valuable adjunct to mammography and ultrasound to detect breast cancer. This was particularly useful in women with dense breast parenchyma. This and other abundant studies have shown that the now called infrared mammography has resurfaced. Another very interesting and exciting new application is for Rheumatology patients. A study published last year in Arthritis Rheumatology proved digital infrared thermal imaging to be a very important tool to assess circulatory function. The study was conducted in a set of patients with Systemic sclerosis and primary Raynaud's problem. Thermal imaging proved to be a good discrimination tool to measure cutaneous blood vessel function these type of patients.
Medical thermal imaging was also proven to be helpful in evaluating the inflammatory state of patients with Graves' ophthalmopathy and the follow-up effect of methylprednisolone pulse therapy. Graves' ophthalmopathy is an autoimmune disease, and patients are treated with immunosuppressive agents if the ophthalmopathy is at an inflammatory state. The inflammation can cause a local increase in temperature than can be monitored by thermal imaging. Other new and exciting medical areas for medical thermal imaging are sports medicine and medical physiology. One of the great advantages of DITI is that it is a non-invasive procedure, with reliable and consistent results. Thermal imaging has proved to be useful as a minimal invasive method to determine the oxygenation level of an internal tissue. A thermographic study in patients with was aimed to observe any possible interaction between the esophageal acid perfusion and the temperature changes of skin surface, They found that add contact with a sensitive mucosa leads to an activation of the sympathetic nervous system in some of the patients with gastro esophageal reflux disease, inducing skin surface hypothermia.
These are just a few examples of the applications of thermal imaging. As seen here, it is a non-invasive technique with a great potential in several medical specialties such as oncology, allergic diseases, angiology, plastic surgery, rheumatology, and many more. Even more, some of the most state of the art equipment are very compact, easy to use and include a complete analysis software solution that make it a must have as an added medical diagnostic tool for many medical specialty practices.
Author: L Baird