Objective
To classify the findings of magnetic resonance imaging of the lumbar interspinous ligaments in relation to the lumbar disc herniation, disc degeneration, and lordosis.

Method
The subjects were 45 herniated intervertebral disc (HIVD) patients and 35 normal subjects on MRI finding. The magnetic resonance features of the interspinous ligament were classified into five categories according to their signal intensities: type 1A (low intensity on T1- and T2- weighted images without hypertrophy of spinal process); type 1B (same signal pattern as in type 1A with hypertrophy of spinal process); type 2 (low intensity on T1- and high intensity on T2-weighted images); type 3 (high intensity on T1-weighted images); type 4 (others).

Results
The most common type in both HIVD patients and normal subjects was type 3. The mean age and disc degeneration grade of the type 1B ligaments were significantly higher. Lordosis of type 1B of L5-S1 interspinous ligament was increased with significant difference.

Conclusion
The classification of the MRI findings of interspinous types didn't show statistical difference between HIVD patients and normal subjects, but was helpful in assessing the degree of the degeneration of the intervertebral disc and age. (J Korean Acad Rehab Med 2002; 26: 449- 455)