Fig. 2

Compressive vertebral venous vascular malformation. Sagittal (a) and axial (b) CT images in the bone window of the thoracic spine demonstrate decreased attenuation of the T4 vertebral body, as well as the left pedicle and transverse process. A characteristic “polka-dot” sign is seen in the vertebral body on the axial image, with high attenuation dots representing replacement of normal cancellous bone by thick, vertical trabeculae (orange arrows) surrounded by vascular lacunes and fatty marrow. Sagittal MR images demonstrate a heterogenous, predominantly high signal lesion on both T1 (c) and T2 (d) weighted sequences involving the T4 vertebral body (orange arrows), with lobular extension into the spinal canal (white arrows). Axial T1 pre- (e) and post-contrast (f) images demonstrate avid enhancement of the lesion. Again, there is extension of the lesion from the vertebral body into the spinal canal, with resulting compression of the spinal cord