Male, 80 years old, with low back pain and spinal stenosis. Since the prior examination, posterior instrumented fusion has been performed with bilateral pedicle screws at L4 and L5. Laminectomy has also been performed at L4-5 with placement of an interbody fusion device. Enhancement within the posterior soft tissues of the operative bed is compatible with scarring.Spinal alignment is anatomic. Mild loss of height of the T12 vertebral body is unchanged. Likewise, moderate loss of height of the L1 vertebral body is unchanged. No significant marrow edema or pathologic marrow replacement or enhancement is seen.The distal spinal cord and conus are within normal limits. The nerve roots of the cauda equina are likewise unremarkable. No epidural abnormalities are seen.A right renal cyst is partially visualized.L1-2: Mild facet hypertrophy. Mild prominence of the dorsal epidural fat. No significant spinal canal stenosis or neuroforaminal narrowing. No interval changes. L2-3: Mild facet hypertrophy and ligamentum flavum thickening. Prominence of the dorsal epidural fat. No significant spinal canal or foraminal stenosis. No interval changes. L3-4: Postoperative changes. Facet hypertrophy and ligamentum flavum thickening. Prominence of the dorsal epidural fat. No significant spinal canal or foraminal stenosis. No other significant interval changes. L4-5: Postoperative changes. Hypertrophy of the residual facets. The previously seen right paracentral disc extrusion has decreased in size though some portion of it remains causing mild effacement of the right ventral thecal sac and slight displacement of the adjacent nerve roots. No significant generalized spinal canal stenosis. Moderate foraminal narrowing, unchanged on the right and slightly improved on the left. L5-S1: Facet hypertrophy and ligamentum flavum thickening. No significant spinal canal or foraminal stenosis.
1.Findings are seen compatible with posterior instrumented fusion from L4 to L5. The instruments are better assessed on CT.2.A right paracentral disc herniation at L4-5 has decreased in size when compared to the prior MRI. There remains a small component of this herniation which causes effacement of the right ventral thecal sac and may contact the adjacent nerve roots. Both neural foramina are moderately narrowed.3.Mild degenerative findings at other levels are not significantly changed. Chronic compression deformity of the T12 and L1 vertebral bodies are unchanged.