RADIOLOGICAL EVALUATION OF DEGENERATIVE LUMBAR STENOSIS

The evaluation of central and lateral lumbar spinal stenosis is equally well performed by CT, CT-myelography and MRI. Stenosis can be quantified and localized in order to optimize orthopedic treatment. Each of these modalities has inherent strengths and weaknesses. CT-myelography is still the best modality for evaluation of central spinal stenosis because absolute stenosis can be more precisely quantified than by plain CT and MRI. Myelography can image the entire spine and localize stenosis that is induced by functional positions. Lateral lumbar spinal stenosis can be localized at the lateral recessus or more distally at the neural foramina. Stenosis of the lateral recessus occurs only at the lower levels of the lumbar spine. Rarely stenosis at the entry of the lateral recessus can be missed by MRI and is only depicted by thin section (1-2 mm) CT. The anatomy and therefore stenosis of the neural foramina are exquisitely demonstrated by direct sagittal MRI.