Proton density sagittal image
T1-weighted axial image
T2-weighted axial image
33 y/o man with radicular pain.
A linear area of increased signal is seen on the sagittal image in the filum terminale on proton density image. On the axial image, a focus of increased signal is seen in the cross-section of the filum. On the T2-weighted image, a chemical shift artifact is seen along the borders of the filum with a black cresent along the right side of the filum, and a bright cresent along the left.
A fatty filum terminale is found in a small percentage (<1%) of normal patients. This finding as well as fibrolipomas of the filum are occationally associate with tethered cords and a low lying conus medullaris.