PT - JOURNAL ARTICLE AU - Ross, J S AU - Blaser, S AU - Masaryk, T J AU - Emory, S E AU - Bolesta, M AU - Carter, J AU - Aikawa, M AU - Modic, M T TI - Gd-DTPA enhancement of posterior epidural scar: an experimental model. DP - 1989 Sep 01 TA - American Journal of Neuroradiology PG - 1083--1088 VI - 10 IP - 5 4099 - http://www.ajnr.org/content/10/5/1083.short 4100 - http://www.ajnr.org/content/10/5/1083.full SO - Am. J. Neuroradiol.1989 Sep 01; 10 AB - Because of the tremendous clinical and physiological importance of anterior epidural scar, an easily produced and reproducible model to assess potential pathways for lessening its formation is a necessity. We speculated whether posterior epidural scar (produced by the less complex surgery of laminectomy alone) could be considered equivalent to anterior scar from an imaging standpoint; that is, enhancement following Gd-DTPA irrespective of scar age. Posterior epidural scar in dogs showed the highest degree of enhancement 1 month after surgery, with a rapid decline thereafter out to 4 months postsurgery to a level equivalent to that of paraspinal muscle. Gd-153-DTPA time/activity curves paralleled the Gd-DTPA findings. Light microscopy showed granulation tissue after 1 month, and mature scar with large amounts of collagen 4 months after surgery. Electron microscopy showed tight capillary endothelial junctions. An appropriate model for epidural scar, which has imaging characteristics similar to human anterior scar, necessitates an extensive lumbar laminectomy with anterior epidural dissection. A simple laminectomy, while easily performed, does not provide a physiologically correct time course of enhancement.