MR imaging of spinal dysraphism.

Spinal dysraphism includes anomalies of midline fusion involving bony, mesenchymal, and neural elements. MR imaging of the spine was performed as the initial imaging technique to determine its role in the evaluation of 31 children when spinal dysraphism was clinically suspected or when radiographs revealed errors of ossification of the posterior elements (spina bifida). Correlation of surgical findings in 17 of 18 abnormal examinations and metrizamide myelography with CT in six of these cases indicated that accurate diagnosis was provided by MR in all instances. Examples of spina bifida aperta (spina bifida cystica)--including myelomeningocele, myelocystocele, and lipomyelomeningocele--and those of occult spinal dysraphism--such as dorsal dermal sinus, spinal lipoma, and tight filum terminale (thickened filum)--are presented. These cases show MR to be a reliable technique in the initial evaluation of these disorders.