American Journal of Neuroradiology, Vol 19, Issue 3 419-426, Copyright © 1998 by American Society of Neuroradiology
ARTICLES |
Surgical site after resection of a meningioma
CA Dolinskas and FA Simeone
Department of Radiology, Pennsylvania Hospital, Philadelphia 19107, USA.
PURPOSE: Our goal was to characterize MR changes over time at the site of meningioma resection in order to determine optimal timing for detecting residual and recurrent tumor. METHODS: Twenty-one patients were studied with enhanced MR imaging during the first 5 postoperative days and additional studies were obtained 3 to 8 weeks after surgery (16 studies), 3 months to 1 year after surgery (17 studies), and 1 year or more after surgery (32 studies). Images were analyzed for residual tumor, membrane enhancement, parenchymal enhancement, edema, and blood collections. RESULTS: Early postoperative images showed extensive, thin membrane enhancement that thickened by 3 to 8 weeks after surgery and that thinned or resolved and became less extensive by 6 months or more postoperatively. Twelve of 20 patients with long-term follow-up studies had membrane enhancement. Thin, serpiginous foci of enhancement in the surgical bed were identified only on early postoperative studies and probably represent gradual thrombosis of feeding vessels. CONCLUSION: Residual foci of meningioma are best detected on studies obtained within the first 5 days after surgery because membrane thickness increases by 3 to 8 weeks after surgery and may obscure a small residual meningioma. Our study confirms the presence of prolonged membrane enhancement after surgery, although it thins with time and becomes confined to the craniotomy site.