Background: Eleven male Georgian soldiers were accidentally exposed to radiation by cesium 137 during their training in a military exercise camp in Lilo, Georgia between November 1996 and May 1997. Objective: The characteristic sequelae of accidental cutaneous irradiation and available diagnostic methods are described. Methods: Magnetic resonance imaging (MRI) of radiation ulcers was performed in all patients; thermography was performed in 2. In 7 patients ulcers and white macules were examined with high-frequency 20 MHz sonography; histologic results were obtained from all patients. Results: Predominant lesions were radiation ulcers in 11 patients and white hairless macules in 7. MRI showed ulcers down to the muscles and an increase of signal intensity in the musculature in 9 cases. The corresponding muscle histology demonstrated vasculitis in 7 patients and necrosis in 2. In 2 patients, MRI signal intensity of the musculature was normal. In 3 patients, 20 MHz sonography showed dermal defects; 1 patient had cutaneous fibrosis. Thermography demonstrated hypothermic zones with extended inflammatory zones adjacent to the radiation ulcers in both patients examined. Conclusion: High-frequency 20 MHz sonography, MRI, and thermography are useful noninvasive methods for diagnosis of the extent of cutaneous radiation syndrome and for therapy planning. (J Am Acad Dermatol 2000;42:453-8.)