Subtle imaging findings in a case of tight filum terminale syndrome.

At 2 months of age, a radiograph of the spine was repeated, and a hemivertebra was demonstrated at the L5 level, as bowel shadows were less prominent (Fig 1). Magnetic resonance imaging (MRI) of the spine was performed to investigate spinal dysraphism at the age of 5 months (Fig 2). The conus was at L2/3 level, and there were no other associated findings of cord tethering (thickened filum, filar lipoma or focal myelomalacia). No intraspinal masses such as lipomas were found. A dermal sinus tract was demonstrated as a dark enhancing band within the subcutaneous fat near the S5 level and communicated with the skin dimple. There was no communication with the thecal sac and no associated dermoid or epidermoid cyst. A repeated MRI spine after 1 year yielded static findings, the conus medullaris was at the L2/3 level and showed no ascent over 1 year. In view of patient’s neurological symptoms and low-lying conus FIG 1. Lumbosacral spine radiograph showing the outline of a hemivertebra at 2 months old, it was obscured on the babygram (not shown)