Index by author

Twenty-eight patients with newly presenting glioblastoma multiforme underwent preoperative conventional imaging and T1 dynamic contrast-enhanced MRI. Parametric maps of the initial area under the contrast agent concentration curve, contrast transfer coefficient, estimate of volume of the extravascular extracellular space, and estimate of blood plasma volume were generated, and the enhancing fraction was calculated. High values of the estimate of volume of the extravascular extracellular space were associated with a fibrillary histologic pattern and increased mitotic activity. This finding is counterintuitive to the standard concept that more proliferative tumors would be more densely packed with cells and have less extracellular space. As the authors point out, this surprising finding requires more investigation to understand whether this relationship will hold, and what the underlying mechanism might be.

Twenty-one patients with previously stented recurrent aneurysms who later underwent Pipeline Embolization Device placement (group 1) were retrospectively identified and compared with 63 patients who had treatment with the Pipeline with no prior stent placement (group 2). Pipeline treatment resulted in complete aneurysm occlusion in 55.6% of patients in group 1 versus 80.4% of patients in group 2. The retreatment rate in group 1 was 11.1% versus 7.1% in group 2. The authors conclude that the Pipeline is less effective in the management of previously stented aneurysms than when used in nonstented aneurysms.