Soft tissue mass in the lumbar region. There are 5 non-rib-bearing lumbar vertebrae in normal alignment. The vertebral bodies and discs are preserved in height. Marrow signal is unremarkable. There is a 2 mm wide midline defect involving the posterior elements of the third or fourth sacral segment with an overlying strand-like extension into the subcutaneous fat, not definitely reaching the skin. The tip of the conus medullaris is at the L2 level. The conus shows normal shape and signal. The cauda equina roots are symmetrically distributed dependently in the thecal sac. There is abundance of epidural fat in the sacral spinal canal, reaching into the lower lumbar canal, posterior to L1 vertebral body. However, there is no fat along the filum terminale.There is no definite abnormality deep to the skin marker which are placed overlying the right posterior superior iliac crest.
1.2 mm defect in the posterior sacral element without associated dural or spinal cord/nerve root abnormality probably represents incomplete fusion.2.The overlying threadlike structure in the subcutaneous fat does not definitively reach the skin and therefore is of doubtful significance. Dorsal dermal sinus classically extends from the skin. 3.There is no definite abnormality deep to the skin marker which are placed overlying the right posterior superior iliac crest.