Syringomyelia and hydromyelia: magnetic resonance evaluation.

Magnetic resonance (MR) imaging of 13 proved cases of syringomyelia or hydromyelia and one case of myelomalacia is described. Most intramedullary cysts were evident on sagittal partial saturation recovery (PSR) images. One cyst containing viscous fluid was not demonstrated on PSR images, but was suggested on a sagittal spin echo image. The case of myelomalacia was indistinguishable from a syrinx on axial PSR and spin echo images. Not all cases of syringomyelia and hydromyelia had the typical MR appearance previously described in the literature. Atypical cysts, spinal cord degeneration, and tumors may have a similar appearance on MR.