Total Thermal Imaging | La Mesa CA Thermal Imaging Center, Clinical Thermography is a simple test of physiology that relies on the sympathetic nerve control of skin blood flow and the ability of the sympathetic nervous system to respond to (and react to) pain, pathology, injury or dysfunction anywhere in the body. While other diagnostics, such as ultrasound, radiography and mammography show the body’s structure or anatomy, DITI (digital infrared thermal imaging) is unique in that it shows physiological and metabolic processes.