Figure 2. a–f.

Case C, hyperdense paraspinal vein sign on CTM. Several representative axial CTM images from case C at T11–12 are ordered from superior to inferior. These demonstrate a linear-curvilinear high attenuation structure extending anteriorly from the right aspect of the thecal sac/nerve root sleeve to the right lateral aspect of the vertebral body, i.e., a hyperdense paraspinal vein sign, compatible with a cerebrospinal fluid venous fistula. The maximum radiodensity of this structure is 419 HU.