Lumbar Spine Imaging: Role in Clinical Decision Making.

Imaging studies are an integral component of the evaluation of the lumbar spine. For each study there is a specific role, an appropriate indication, and a correct time for utilization during the course of a patient's illness. The physician must know the specificity and sensitivity of each test, as well as the prevalence of abnormal findings in asymptomatic persons, to properly order and interpret the results of the studies. Many errors in decision making arise, not from misinterpretation of what is seen on imaging studies, but rather from misuse of imaging information in the clinical decision making process. Because all neurodiagnostic imaging modalities reveal abnormalities in at least a third of asymptomatic persons, the use of these tests for general screening is dangerous. The challenge for the future is to be able to better correlate what is seen on imaging studies with the patient's symptoms. Obtaining these expensive studies too early in the treatment of self-limited disorders is costly and often misleading for both the physician and the patient. The authors outline an approach to the judicious timing of imaging studies and discuss pitfalls in their interpretation in the evaluation of degenerative diseases of the lumbar spine.