Purpose: In recent years, many reports have described spontaneous resorption of lumbar disc herniation evaluated with Gd-enhanced MRI. We also found retrospectively that sequestrated lumbar disc herniation with Gd-enhanced MRI would disappear, and that patient with this type of lumbar disc herniation would improve clinically. But there is a question that Gd-enhanced MRI is really needed to speculate the prognosis of sequestrated lumbar disc herniation. The purpose of this study is to clarify the prognostic value of Gd-enhanced MRI for sequestrated lumber disc herniation.

Materials and methods: Since Nov. 1995, 22 patients of sequestrated lumber disc herniation were treated non-operatively under the speculation of getting good clinical result prospectively. From Nov. 1995 to Oct. 1997, 9 patients with sequestrated lumbar disc herniation with ring-enhancement on Gd-enhanced MRI were treated non-operatively (Group A). From Nov. 1997 to July 2000, 13 patients with sequestrated lumbar disc herniation were treated non-operatively without Gd-enhanced MRI examination (Group B). Clinical results and the last MRI findings of Group A were compared with that of Group B.

Results: In Group A, all cases were treated non-operatively and all of them improved clinically within a month of the first MRI examinations. Mean period of NSAID administration was 37 days (range 14–67 days), and the last MRI examinations revealed that the herniated masses disappeared in 5 cases and that the size of herniations diminished in 4 cases. All of 9 cases obtained good clinical results. In Group B, all cases were treated non-operatively but one, whose clinical symptoms were not improved within a month of the first MRI examination. Mean period of NSAID administration was 38 days (range 7–110 days), and the last MRI examinations revealed that the herniated masses disappeared in 5 cases and that the size of herniations diminished in 5 cases. Remaining 2 cases, the second MRI was not examined for some reasons. All of 12 cases obtained good clinical results. There were no differences between Group A and Group B by means of clinical results.

Conclusions: Gd-enhanced MRI is not needed to speculate the prognosis of sequestrated lumbar disc herniation. In the case of sequestrated lumbar disc herniation, good clinical result could be obtained without Gd-enhanced MRI examination at the first MRI examination.