 The conus terminates at approximately the lower L4 level, the determination including an expansile CSF signal intensity cystic structure along the distal conus, which measures 4 x 5 mm in greatest axial dimensions, x 1.8 cm CC. This scan the L2-L3 to the lower L4 level. In addition, there is a prominent rounded area of fat signal intensity just distal to this cystic structure which measures up to 5 x 4 mm which extends from the lower L4 level to at least S1-S2, consistent with a filar lipoma. On prone imaging, there is only slight ventral motion of the distal cord and conus.A skin surface marker is identified in the L5-S1 level down to the upper aspect of the gluteal cleft which presumably designates a sacral dimple. At the mid S3 level, there is a minimal underlying linear T1/T2 hypointensity (1701/34), although no clear patent tract is identified. The linear abnormality extends deep to the superficial aspect of the gluteal musculature without definite direct connection to the spinal canal contents. There is questioned linear T1 hypointense signal along the midline of the L5 posterior elements which could suggest a minimal occult dysraphism. No definite significant spinal dysraphism is appreciated on this MRI.The thoracic and lumbar spine are in normal alignment. The vertebral body and disk heights are well-maintained. No worrisome focal marrow signal abnormality is appreciated. The spinal cord is of normal caliber and signal.There is no significant disk bulge, herniation, spinal canal or foraminal stenosis within the spine. A few rounded T2 hyperintense structures within the pelvis bilaterally likely relate to the ovaries.
1.Approximate conus termination at the the lower L4 level, although exact level is difficult to determine secondary to the associated conus cyst. This most likely represents an associated conus syrinx, less likely a terminal ventricle or cystic neoplasm, although postcontrast images through the conus is recommended for complete evaluation.2.Additional finding of focal filar/intraspinal lipoma measuring up to 5 mm with only mild ventral motion of the distal cord and conus on prone imaging. Please correlate clinically for possible tethered cord.3.Small subcutaneous sinus tract suggested just deep to the caudal aspect of the skin surface marker presumably in the location of the sacral dimple at the approximate mid S3 level, without definite connection to the spinal canal contents. Questioned linear cleft in the midline of the posterior elements of L5. CT would better delineate any possibility of occult dysraphism.4.Unremarkable MRI of the thoracic spine.