Fig 1. Four selected images at TE of 19, 38, 56, and 75 ms from the modified FSE sequence illustrate the loss of signal intensity from the spinal tissues and L4-L5 disk with increasing TE. Disk tissue loses signal intensity less rapidly than vertebrae. The T2 relaxation time, the length of time required for the signal intensity to diminish by 50%, is calculated for each voxel from 16 such images.