Thermal Imaging Today and Its Relevance to Diabetes
In diabetes mellitus, circulatory dysfunction
have been performed with low-cost radiation
thermometers. Lavery and Associates (18)
can occur in the feet as well as hands, which
carried out a clinical trial involving 173
can lead to skin ulceration (Figure 5). Thermal
diabetes patients with a history of ulceration.
imaging has been used as one method to
The patients were instructed to self-monitor
monitor skin temperature in the area of
by measuring temperatures on the great
ulceration, which again can be a means of
toe; first, third, and fifth metatarsal heads;
assessing the efficacy of treatment used
midfoot; and heel on a regular basis. They
to improved the perfusion to the affected
were instructed to call the study nurse if a
limb. The allocations of thermography and
temperature difference of 4 ºF was found.
thermometry in lower extremity wounds and
Over 50% of patients did call
the associated vascular complications
the nurse, and 8% of them went
have been reviewed by Bharara and
on to develop ulcers. In another
coworkers, (15) who also studied the
study, Armstrong and coworkers (19)
low-cost technology of contact liquid
These studies
evaluated the effectiveness of home
crystal thermography.
clearly
temperature monitoring over an
demonstrate
Fushimi and colleagues1 (6) proposed a
18-month period with a randomized
that high
new index of autonomic neuropathy
controlled trial involving 225
temperature
in diabetes mellitus by using a warm
patients. They also found that 8.4%
gradients
water bath immersion for one leg
ulcerated over the study period.
between
while studying the other using infrared
Those patients who ulcerated had
feet may
thermography. They noted that
a temperature difference that was
predict the
thermography was one of the most
4.8 times greater at the site of
onset of
reliable, reproducible, and noninvasive neuropathic
ulceration in the week before the
methods for detecting and monitoring
ulcers appeared than did a random
ulceration...
sympathetic abnormalities in this
seven-consecutive-day sample of 50
disease. Early diagnosis of neuropathic
other subjects who did not ulcerate.
joint disease is important and provides
These studies clearly demonstrate
...simple
the opportunity to introduce prompt
that high temperature gradients
temperature
protective treatment. A group of
between feet may predict the onset
measurements
orthopedic surgeons successfully
of neuropathic ulceration and that
recorded
in
used thermography to detect early
simple temperature measurements
home
presence of warmth associated
recorded in home monitoring is of
montoring
with early neuropathic disease and
benefit in the management of these
concluded that infrared thermography is a benefit
patients.
in the
was a reliable diagnostic tool in this
management
Some early work was carried
application. (17)
of these
out in Scotland to assess the use
patients.
Thermal symmetry in the feet is a
of infrared thermography in the
normal finding in healthy subjects. It
determination of amputation level in
those patients whose limbs could not
is interesting to note that some studies
Current Pedorthics | September/October 2019
25