Normal appearance of spinal bone marrow in a 45-year-old woman: T1-weighted (500/11, TR/TE) (A) and T2-weighted, fat-suppressed fast spin echo (4000/96, TR/TE, ET 16) (B) sagittal MR images of the lumbar spine. Note increased signal of the vertebral bodies, relative to the intervertebral discs in (A) and increased deposition of fatty marrow around the basivertebral veins (arrowheads). On the T2-weighted image, normal intervertebral discs are brighter than the vertebral bodies; low signal in the L4-L5 and L5-S1 discs is due to degenerative changes (arrows).