Degeneration of the intervertebral disk complex begins early in life and is a consequence of a variety of environmental factors as well as of normal aging. Degeneration of bone and soft tissue spinal elements is the most common cause of spinal stenosis. The term "degeneration" as commonly applied to the spine covers such a wide variety of clinical, radiological and pathological manifestations that the word is really only a symbol of our ignorance. Computed tomography and myelography have long been used for diagnosing the effects of degenerative diseases' of the lumbar spine. Despite the continuous improvement in magnetic resonance scanning for this purpose, computed tomography can provide excellent screening for disk herniation and spinal stenosis.