Though there has been an array of methods to evaluate the extent of sarcoidosis, it is generally difficult to detect central nervous system involvement. Recently it has become accepted that 18F-FDG PET is more sensitive than gallium scintigraphy in finding sarcoid lesions, however its usefulness and limitations for detecting sarcoidosis in the central nervous system, especially in the spinal cord, has rarely been investigated. Two patients with pathologically confirmed sarcoidosis manifested spinal symptoms. We conducted 18F-FDG PET along with conventional imagings (...) before and after treatment. Abnormal FDG uptakes which could not be detected by gallium scintigraphy were shown in the spinal cords in both patients. These abnormal uptakes were diminished in accordance with clinical improvement after treatment. Our findings suggest that 18F-FDG PET is effective in detecting and tracking the activity of spinal sarcoidosis. (shrink)