A, CT myelogram and myelogram showing minimal filling of a large right S2 Tarlov cyst with a narrow neck. A, CT myelogram and myelogram showing minimal filling of a large right S2 Tarlov cyst with a narrow neck. There is significant remodelling of S2 and S3. B, With 18-ga spinal needles in place, one deeper than the other, partial aspiration has developed an air-fluid level. C, Injection of fibrin fills the cyst 80%. The volume of fibrin injected is close to the volume of CSF aspirated. K. Murphy et al. AJNR Am J Neuroradiol 2016;37:373-379 ©2016 by American Society of Neuroradiology