Fig 6. Axial T2 of the spine from (A) 18-week, (B) 22-week, and (C) 41-week fetuses. The ossification centers of the posterior elements are first seen at the base of the lamina (arrowhead). With increasing gestation, ossification is seen to proceed posteriorly to the remaining lamina, anteriorly to the pedicle and posterior aspect of the vertebral body, and laterally to the transverse process.