Increased left lower extremity pain, numbness and urinary retention, spinal stenosis at lumbar region.Clinical question: Evaluate for nerve root compression. L1 is designated as the first nonrib-bearing lumbar vertebra. L5 and S1 demonstrate transitional lumbosacral morphology. Vertebral body heights are within normal limits. Alignment is within normal limits. There is redemonstration of a chronic pars fracture involving L4 on the right, which is better seen on prior CT. There is a small focus of T1 and T2 hypointensity in L3 vertebral body, nonspecific and without correlate on the outside CT. No aggressive bony lesions are detected. The conus medullaris is normal in position terminating at L1-L2.Multilevel degenerative changes are seen, as described below:L1-L2: No significant disc disease. No spinal canal or neural foraminal stenosis.L2-L3: There is ligamentum flavum thickening and bilateral facet arthropathy. No spinal canal or neural foraminal stenosis.L3-L4: There is loss of T2 signal intensity of the disc along with minimal disc bulge and a small central annular fissure/protrusion. There is ligamentum flavum thickening and bilateral facet arthropathy. No spinal canal or neural foraminal stenosis.L4-L5: There is mild loss of disc height with mild loss of T2 signal. There is mild disc bulge. There is evidence of previous surgery with findings of laminectomy. There is severe hypertrophy of the left facet joint, fluid in the facet joint and thickening of ligamentum flavum. In addition, the facet complex and the adjacent soft tissues are edematous. There is moderate right facet hypertrophy. These findings contribute to produce severe transverse spinal canal narrowing with probable nerve root impingement. There is mild bilateral narrowing of the neural foramina.L5-S1: There is a mild disc bulge with moderate bilateral foraminal narrowing. There is bilateral facet arthropathy. S1-S2: No significant neural foramen narrowing or spinal canal stenosis.Paraspinous soft tissues are within normal limits.
Degenerative disc changes predominantly involving L4-L5 with severe left and moderate right facet arthropathy, resulting in severe transverse spinal canal narrowing and possible nerve impingement at this level. There is edema of the left facet complex at this level likely indicating a component of acute inflammation.At L5-S1, there is moderate bilateral neural foraminal narrowing. Additional foraminal narrowing as detailed above.