[Imaging strategies in common low back pain].

Imaging strategy varies according to the background of acute or persistent low back pain. In case of acute low back pain with associated symptoms of a cauda equina syndrome or any atypical clinical signs PA and lateral radiographs of the lumbar spine are required. An additional MRI examination is often necessary, even with negative radiographs. In the other cases, radiographs are only obtained when the low back pain persists longer than 7 weeks. Secondary, MRI may be performed in case of worsening and persistence of the clinical symptoms or if a specific low back pain is suspected. In case of chronic low back pain, with a severe socio-professional impact or a planed invasive treatment, plain films of the lumbar spine must be obtained, eventually with additional MRI examination.