RT Journal Article SR Electronic T1 Decreased Diameter of the Optic Nerve Sheath Associated with CSF Hypovolemia JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 863 OP 864 DO 10.3174/ajnr.A1027 VO 29 IS 5 A1 A. Watanabe A1 T. Horikoshi A1 M. Uchida A1 K. Ishigame A1 H. Kinouchi YR 2008 UL http://www.ajnr.org/content/29/5/863.abstract AB SUMMARY: The subarachnoid space around the optic nerve can be detected by fat-saturated T2-weighted MR imaging of the orbit, and dilation of this space reflects increased intracranial pressure. We examined 3 patients with CSF hypovolemia with MR imaging of the orbit and measured the optic nerve sheath diameter before and after treatment. We showed that the subarachnoid space is decreased in patients with CSF hypovolemia and the usefulness of this finding.