Figure 2

Severity of EL can be determined from physical features. (A) Axial image through the body of L5 with early EL. The L5 nerve roots are visible from thecal sac to Lateral Recesses. Epidural Lipomatosis (EL) enhances the visibility of the L5 roots. The arrow points to the indentation of the thecal sac. (B) Epidural fat tethering dural sac producing stellate appearance and moderate EL. (C) Axial MR image through the body of S1 with severe EL. The arrow points to the thecal sac in the shape of a Y (pathognomonic for severe EL). The buttock muscles are infiltrated with fat and the overlying subcutaneous tissue is excessive. (D) Axial MR image through the body of L4 with EL, compressing the roots and thecal sac. Since the neural elements normally occupy a larger area of the spinal canal at L4 than L5/S1, the compression by EL is considered severe.