Table 1 Clinical guidelines for use of lumbar spine imaging

International guidelines advise no imaging for acute low back pain that has lasted < 4 to 6 weeks [5–8] and no [5, 7] or optional [5] imaging for chronic low back pain, unless one or more "red flags" are present (increased chance of serious disease).

Such "red flags" or clinical criteria for lumbar spine imaging include [1–8]:

• Age at onset of pain < 20 years or > 55 or 50 years

• Non-mechanical pain: constant/increasing, not better in rest

• Thoracic pain

• Generally unwell, weight loss

• Major trauma, history of cancer

• Steroid use, immunosuppression, drug abuse

• Widespread neurological signs or symptoms

• Structural spinal deformity

• Marked morning stiffness for > one hour

• High erythrocyte sedimentation rate (> 20 mm/hr)