Even when the radiographic findings are consistent with clinical presentation, the magnitude of radiographic findings does not necessarily correlate with dlinical severity and outcome, and clinical improvement may not correlate with resolution of the radiographic defect [54.55). As an example, in one follow-up of a trial of 283 patients with lumbar disk herniation and sciatica who had undergone surgery, MRI at one-year follow-up showed disk herniation in 35 and 33 percent of patients with favorable and unfavorable outcomes, respectively [55). Some findings on MRI are clinically insignificant or of uncertain significance. These include: