A comparison of radiographic signs of degeneration to corresponding MRI signal intensities in the lumbar spine.

OBJECTIVES

To evaluate plain film radiographic findings of lumbar intervertebral disk degeneration.

DESIGN

A cross-sectional observational design was employed. Contingency tables were constructed to evaluate the relationships between radiographic findings of degeneration and the corresponding MRI signal intensities of the inner intervertebral disk.

SETTING

Twenty-four consecutive cases were retrospectively selected from an MRI imaging center.

PATIENTS: No exclusion was made on the basis of age or sex.

MAIN OUTCOME MEASURES: Radiographic findings of IVD degeneration include: Narrowed disk space, osteophyte formation, end-plate sclerosis, vacuum phenomenon, end-plate irregularity and Schmorl's node formation. The inner IVD signal intensity of the sagittal T2-weighted MRI image was visually categorized by three radiologists. The signal intensities were divided into low, medium and high categories.

MAIN

RESULTS

Visually reduced disk height, osteophytes and eburnation all demonstrate significant relationships with MRI signal intensity. Due to their infrequency, no significant relationships could be found with vacuum phenomena, end-plate irregularity, and Schmorl's nodes when compared to MRI signal intensity.

CONCLUSIONS

In conclusion, visually reduced disk height is frequently associated with decreased signal intensity and, therefore, significantly indicates internal disk derangement. Osteophytes are more commonly present when the signal intensity is low. However, high signal intensity is associated with osteophytic change as well. Therefore, osteophytic change is less sensitive and accurate to early inner disk degenerative change. When osteophytes and reduced disk height are present together, a stronger prediction of degeneration is possible then when either finding is present alone. Due to their infrequency, eburnation, vacuum phenomena, end-plate irregularity and Schmorl's nodes are less helpful indicators of degeneration.