Biomedical Engineering Reference
In-Depth Information
Fig. 1.41.
An angiologic thermatome of a femoral artery obstruction.
Left:
astan-
dardized thermogram.
Right:
asymmetry detection thermogram ([right leg] - [left
leg], displayed on the left side)
it must be emphasized that the name is not based on the original concept of
the angiosome, which is derived from the region of the body used for source
arteries in skin flap transplantation [62]. Figure 1.41 shows a low-temperature
area on the left foot caused by obstruction of the left femoral artery.
Functional Angiologic Thermatomes.
The skin blood flow is controlled
by the adrenergic sympathetic nervous systems. In particular, the vasomo-
tor sympathetic nerves in the distal regions of the extremities are composed
only of contractile nerve endings, which control body temperature by vascu-
lar contraction or dilatation. Images with lower temperatures are sometimes
not a result of mechanical obstruction of peripheral arteries, but are due to
functional obstructions, such as the case of Raynaud's syndrome. The term
functional angiologic thermatome
indicates that the lower- or higher-temper-
ature areas are a reflection of functionally reduced or increased blood flow,
respectively. In Fig. 1.42, the left half of the body is at a higher tempera-
ture than the right. The patient suffered from cervical syringomyelia and
shows left-side Horner's syndrome. The pattern indicates a lack of sympa-
thetic control in the left half of the body, and resembles a thermogram in
stellate ganglion block.
Dermatomal Thermatomes.
The sensory nerves are distributed at a par-
ticular vertebral level, with the segment referred to as a
sensory dermatome
.
As the vasomotor centers of the vertebrate are present in each somatic seg-
ment, skin-temperature distribution within the segments is usually called a
thermatome. Here, they are referred to as
dermatomal thermatomes
; i.e.,
thermally expressed sensory dermatomes. The terms are usually applied to
the lower-temperature regions produced as a result of radiculopathy. The
sensory segment of skin exhibiting chronic pain coincides with the lower-
temperature area of the extremities (especially the legs and feet). Figure 1.43
