Introducing
Thermal Imaging Basics
Thermal imaging in
the form practiced by Australian Thermal
Imaging Pty Ltd
is the quantification and recording of the skin's surface temperature by
non-contact sampling and analysis of the infrared emissions from that
surface. This data is compiled by a computer into a thermal image.
Thermal imaging is
non-contact, emits no ionising radiation, and as such, is non-invasive.
Because it is
non-contact, there is no pain involved in thermal imaging.
A
Thermal Imaging Scanner (or camera) measures infrared energy (heat)
radiated from a body, accurately converting it to thousands of
equivalent temperature readings.
On a thermogram, Whites,
reds and yellows typically represent the warmer end of the temperature range
being displayed.
Blacks, blues and
greens generally represent the cooler end of the same range.
A computer program
assigns particular temperature ranges a particular colour, and then
displays the now colorised temperature readings as a colour image which
is a thermogram or thermograph.
The Australian
Thermology Association set a sixteen colour palette including black and
white covering an eight degree range as a standard for all thermograms.
This means that any one colour covers a band of temperature just half a
degree centigrade wide. This is covered in the
ATA code of practice.
Cold Patterns
(hypothermia)
(Hypo -deficient,
thermo -temperature)
Cold patterns
typically represent a decrease in blood supply. Nerve irritation or
dysfunction and restricted circulation can produce thermographic cold
patterns. Cold asymmetries (lack of symmetry) mostly result from
(sympathetic) nerve irritation. Nerve irritation can trigger muscles
around the blood vessels to contract, even virtually stopping the supply
of blood to an effected area.
Hot Patterns
(hyperthermia)
(Hyper -excessive,
thermo -temperature)
Heat patterns
typically represent an increase in blood supply and local tissue
temperature, which is the definition of inflammation. Wounds, blood
pooling, complete nerve malfunction or abnormal blood vessel
formations/alterations typically produce thermographic heat patterns.
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