Infections of the spinal column--spondylodiscitis.

Infectious spondylodiscitis is an infection of the intervertebral disc and the adjacent vertebral bodies due to the introduction of a pyogen, usually by the haematogenous route. Plain film radiography (which is usually normal in the early stages) shows blurring of the vertebral endplates and a loss of disc height that progresses quickly. MRI is the examination of choice, as it detects oedema within the trabecular bone very early, before the onset of destruction. Injection of a contrast medium with fat signal saturation improves detection and visualisation of the spread of infection in the soft tissue and epidural space. Imaging can also be used to guide a needle aspiration to investigate the infective agent.