The MR studies of three histologically proven spinal neurilemmomas and
neurofibromas were reviewed retrospectively. There were two benign
neurilemmomas (schwannomas) and one neurofibroma. The common
characteristic of these cases was a central low intensity focus
(”dot”) seen on postcontrast T1-weighted imaging. The low intensity
foci corresponded histologically to a congeries of changes including
edema, microcysts, foam cells, hyalinization of blood vessels, old
hemorrhage, and dystrophic calcification
