Résumé : PURPOSE: To evaluate the use of postembolization gadolinium-enhanced MR imaging as a means to judge the efficacy of tumor embolization. METHODS: Fifteen patients with meningiomas were prospectively studied. The following data were evaluated for each tumor: the percentage of vascular supply to the tumor arising from the internal and external carotid arteries; the percentage of the tumor embolized as judged by angiography, by MR imaging, and by CT scanning; the estimated blood loss according to the surgeon; and histologic evidence of necrosis as seen by the neuropathologist. RESULTS: The data reveal an excellent correlation between the amount of tumor embolized as estimated by MR and both the estimated blood loss at time of surgery and the presence of histological necrosis in the specimen. CONCLUSIONS: Postembolization gadolinium-enhanced MR is an excellent means to evaluate the efficacy of an embolization and offers certain advantages over CT and angiography. One important advantage of this technique lies in the fact that it can be performed immediately postembolization.