Discography is currently used to determine whether the disk is the source of pain in patients with predominantly axial back or neck pain. During discography, contrast is injected into the disk and the patient’s response to the injection is noted; provocation of pain that is similar to the patient’s existing back or neck pain suggests that the disk might the source of the pain. Computed tomography (CT) is usually performed after discography to assess anatomical changes in the disk and to demonstrate intradiscal clefts and radial tears.