The postoperative spine. Magnetic resonance imaging.

MRI is rapidly becoming the imaging modality of choice in the diagnostic assessment of patients with persistent or recurrent symptoms following spinal surgery. It displays the normal postoperative findings as well as most causes of FBSS. MRI can differentiate persistent or recurrent disk herniation from postoperative scar formation with a greater degree of confidence than other imaging modalities. MRI can determine clinically important functional instability when CT and conventional radiography are inconclusive. This can be particularly helpful in evaluating the patient with multiple lumbar surgeries. MRI can also determine the presence of other causes of the FBSS such as lateral spinal stenosis, arachnoiditis, fat graft compression on the thecal sac, and presence of postoperative hematoma or postoperative infection.