which is a sagittal (from the side view) T2 Weighted MRI lumbar image, demonstrates two types of disc herniation: the L5/S1 disc has suffered a 9mm disc extrusion (red arrow) that is not contained by the PLL. The L4/5 disc has suffered a smaller 4mm disc protrusion (green arrow) that is contained by the PLL. The L3/4 (blue arrow) is completely normal and has no disc material projecting posteriorly into the epidural space. Also note that the L3/4 disc is white in color, which indicates it is non-degenerated (i.e., full of water and healthy proteoglycan). The two herniated discs (L4/5 & L5/S1) are "black" on this MRI image, which indicates disc desiccation (lack of water and proteoglycan) and is termed "degenerative disc disease" (DDD), which is usually a precursor to disc herniation for it weakens the annulus which contains the pressurized nuclear material.

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