[Modern intervertebral disk diagnosis].

Recent advances in our knowledge of the pathophysiology and function of the intervertebral disc, in combination with the use of CT and MRI have changed radiological diagnostic algorithms and enlarged our diagnostic scope. Microfissures in the cartilage endplates of the disc and in the endplates of the vertebral bodies and anulus fibrosus are the sequelae of loss of hydration of the nucleus pulposus leading to instability and abnormal load stress. MRI shows these early degenerative changes in the disc, but also reactive processes in the disc and the neighbouring vertebral bodies. On conventional X-rays only segmental malfunctions are visualized. Protrusion and prolapse can be recognized very well by CT, but best of all by MRI. Myelography and discography are very invasive and rarely used. Very important is that protrusion and prolapse are very often diagnosed without any clinical symptoms and that both may heal without any treatment. Therefore conservative treatment of prolapse and/or protrusion is the management of choice. Blastoma and infection of the disc are found in the vast majority of cases only in combination with corresponding diseases of the vertebral bodies. The only important exception are small children, in whom primary bacterial infection of the disc is well known.