[MRI diagnosis of intervertebral disk disease].

Magnetic resonance imaging (MRI) is the leading diagnostic procedure for disk pathology and has overtaken other imaging modalities in frequency of use. However, one must be cautious not to overinterpret small abnormalities that are also frequent in asymptomatic subjects. There is conflicting evidence about the correlation of high-intensity zones with clinical symptoms. Bulging disks and protrusions are a common finding in asymptomatic individuals, whilst extrusions are almost always accompanied by back pain and sciatica. In patients with back pain or sciatica, MRI is indicated after failure of conservative management or neurological deterioration. Contrast-enhanced MRI is well suited to differentiate a recurrent disk extrusion from epidural fibrosis. In all cases suspicious of tumor or infection, MRI is indicated as a first-line investigation. The indications and pitfalls of the state of the art of MRI are delineated in this article.