Sonography in the diagnosis and management of anterior sacral meningocele.

Four cases of anterior sacral meningocele (ASM) are described, with comparisons between radiological and sonographic findings. On plain films, 2 cases showed the classic scimitar sign, and 1 case showed a defect in the anterior sacrum. The other lesion appeared radiologically to be a purely intrasacral meningocele. Myelography outlined part of the ASM in two cases. Sonography demonstrated the anterior sacral cysts in all cases. Sonography is a noninvasive method of monitoring progress or contraction of a lesion, and it can be used to demonstrate any associated pathology. The combination of plain-film appearances and sonographic findings should be sufficient for diagnostic purposes. If an operative procedure is contemplated, then myelography may be performed in an attempt to outline the stalk.