The curtain sign (or draped curtain sign) in neuroimaging refers to the appearance of a vertebral body mass that extends to the anterior epidural space.

If a vertebral body lesion extends posteriorly to the anterior epidural space, it displaces the posterior longitudinal ligament. However this is limited by that strong medial fixation, giving a bilobular intracanalar aspect in the axial images, which is commonly called curtain sign (or draped curtain sign).

Photograph courtesy of Roger Bickle, Melton Mowbray, UK.