The thecal sac, also known as the dural sac, is a membrane sheath that covers the spinal cord and the surrounding cerebral spinal fluids (CSF). Indentation means there is some compression of the thecal sac itself, but it does not appear to affect the nerves.
If you have neck pain, you may be interested in 50 Questions About Cervical Thecal Sac Compression.
Also known as: Thecal sac effacement
