Neuroimaging in low back pain.

Patients commonly present to family physicians with low back pain. Because the majority of patients fully or partially recover within six weeks, imaging studies are generally not recommended in the first month of acute low back pain. Exceptions include patients with suspected cauda equina syndrome, infection, tumor, fracture, or progressive neurologic deficit. Patients who do not improve within one month should obtain magnetic resonance imaging if a herniated disc is suspected. Computed tomographic scanning is useful in demonstrating osseous structures and their relations to the neural canal, and for assessment of fractures. Bone scans can be used to determine the extent of metastatic disease throughout the skeletal system. All imaging results should be correlated with the patient's signs and symptoms because of the high rate of positive imaging findings in asymptomatic persons.