Infrared thermal imaging in medicine

Abstract

This review describes the features of modern infrared imaging technology and the standardization protocols for thermal imaging in medicine. The technique essentially uses naturally emitted infrared radiation from the skin surface. Recent studies have investigated the influence of equipment and the methods of image recording. The credibility and acceptance of thermal imaging in medicine is subject to critical use of the technology and proper understanding of thermal physiology. Finally, we review established and evolving medical applications for thermal imaging, including inflammatory diseases, complex regional pain syndrome and Raynaud's phenomenon. Recent interest in the potential applications for fever screening is described, and some other areas of medicine where some research papers have included thermal imaging as an assessment modality. In certain applications thermal imaging is shown to provide objective measurement of temperature changes that are clinically significant.

Variability in peripheral rewarming after cold stress among 255 healthy Norwegian army conscripts assessed by dynamic infrared thermography

“…Our use of 20°C water and an immersion time of the gloved hand of 1 min resulted in lowering the skin-temperature of the fingers by on average 6.7°C. This cold challenge is in accordance with proposed standards when investigating vasoactive responses in fingers [11,19]. …”

“…Using average temperature lines on the dorsum of the fingers as ROI serve as a stable and reproducible investigating strategy [11], despite possible thermal asymmetry. The straight-line ROI of the fingers used in this study also covered the fingernail, which strictly speaking cannot be included as true skin temperature.…”

“…In Raynaud’s phenomenon and other peripheral circular disturbances, infrared thermography (IRT) has been used to define potential endpoints in therapeutic trials that overcome the limitation of self-reported assessment [10]. Dynamic infrared thermography (DIRT), involving the use of thermal provocations tests, has been used in investigating circulatory disturbances especially in the hands such as vasospastic disorders seen in Raynaud’s phenomenon [11–13]. …”

Development of a handheld fluorescence imaging device to investigate the characteristics of protoporphyrin IX fluorescence in healthy and diseased skin

“…Skin temperature varies at different body sites and can be displayed with infrared imaging cameras 33 [http://www.rnhrd.nhs.uk/page/92]. Typical temperatures of the head and the neck have found to be 35-37°C 34,35 , the lower leg and the "edge" areas of the feet and the hands have lower temperatures of 30-33°C. We estimated typical temperatures of healthy skin at the lesions sites using infrared thermal images reported in the literature (SI 5) 35,34,36 and correlated this with the fluorescence measurements.…”

Reliability and validity of skin temperature measurement by telemetry thermistors and a thermal camera during exercise in the heat

“…Infrared thermometry is another technique that is used in research (Costello et al 2012) and clinical environments (Ring & Ammer 2012) where T SKIN is an important variable to measure. Thermal cameras receive and process infrared radiation emitted from a surface, using this information to display the production and dissipation of heat.…”