Role of screening of whole spine with sagittal MRI with MR myelography in early detection and management of occult intrasacral meningocele

OBJECTIVE: We evaluated the role of screening of the whole spine by sagittal magnetic resonance imaging (MRI) along with MR myelography in early detection and management of occult intrasacral meningocele. MATERIALS AND METHODS: A prospective and retrospective analysis of MRI and MR myelography studies of the whole spine over a period of one year was performed. RESULTS: Thirty cases with sacral meningeal cysts were seen. On MRI, six patients (three males, three females) fulfilled the criterion of occult intrasacral meningocele. These patients showed a cyst of cerebrospinal fluid (CSF) signal intensity in the sacral canal below the dural sac. This cyst communicated with the thecal sac through a narrow pedicle. Fat signal intensity in the filum terminale and occult sacral dysraphism in the form of an absent or hypoplastic neural arch was observed in all the patients. Low-lying conus medullaris with thick filum terminale was seen in five of these six patients. Excision of the cyst with the release of filum was performed in two patients with a favorable outcome. CONCLUSION: Screening MRI with MR myelography of the whole spine may play a role in the early detection and management of occult intrasacral meningocele. The commonly associated thick filum terminale and low-lying conus medullaris may be missed otherwise that may lead to a progression of symptoms.