n. a technique for measuring and recording the heat produced by different parts of the body by using photographic film sensitive to infrared radiation. The picture produced is called a thermogram. The heat radiated from the body varies in different parts according to the flow of blood through the vessels; thus areas of poor circulation produce less heat. On the other hand a tumour with an abnormally increased blood supply may be revealed on the thermogram as a ‘hot spot’. The technique was formerly used in the diagnosis of tumours of the breast (mammothermography) before the development of more sensitive techniques (see mammography).... thermography