Liquid crystal thermography of the spine and extremities. Its value in the diagnosis of spinal root syndromes.

Cholesteric liquid crystals are special compounds that display specific color changes in response to variations in temperature. Their responses can be graphically demonstrated by means of color thermography. A new color contract thermographic technique is described utilizing liquid crystals embedded in elastic flexible sheaths. These sheaths, when inflated, conform to the varied contours of the torso and extremities and, therefore, the new thermographic technique is especially well suited to the study of the skin dermatomes and myotomes. Typical heat patterns have been observed in root compression syndromes and particularly at the S-1, L-5, L-4, C-6, C-7, and C-8 levels. A high degree of anatomic accuracy can thus be achieved, comparable to or better than can be achieved by electromyography or myelography. Liquid crystal thermography can serve to screen patients for myelography and can complement myelography in identifying clinically significant abnormalities. The imaging technique correlates well with clinical and surgical findings, and constitutes one of the first attempts by means of a concomitant study of the body dermatomes to objectively document the subjective complaint of pain.