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MR demonstrates a typical appearance of the bamboo spine, on coronal STIR and T1 weighted images facet joints and both sacroiliac joints were ankylosed.

Dural sac shows widening (dural ectasia) with multiple dorsal dural diverticula causing an erosion of the posterior vertebral elements.

Conus medullaris is tethered at the level of the L1 to the dorsal aspects of the spinal canal and there is adhesion of the cauda equina nerve roots to the posterior wall of the dural sac.