Thermal Imaging Today and Its Relevance to Diabetes
Figure 1: Thermographic examination of hands.
Great progress has been made both in the
understanding of the physiological conditions
required to harness this technique as a
medical investigation and in the technology
itself.
The early scanning cameras were not as
reliable or stable as those available today.
Images of heat distribution, where white
represents hot and black represents cold,
were obtained. Two important factors in
the creation of such images are thermal and
spatial resolution. The former is the ability of
the imaging system to discriminate between
small areas of differing temperatures, and the
latter relates to image quality. To overcome
the slow scan speed often required with
the earlier camera systems, multi-element
detectors were introduced. However, there
was still a compromise needed between high
speed and low resolution or low speed to
obtain high resolution. (6)
Modern thermal imaging cameras now
provide high speed and high resolution.
Furthermore, the stability of the earlier
cameras has improved dramatically, and
calibration of the imager against a stable
temperature reference can be achieved
to ensure reliability. This is of particular
importance when repeated investigations are
made with this technique. (7)
Current Pedorthics | September/October 2019
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