BACKGROUND AND PURPOSE:A subset of patients with malignant glioma develops conspicuous lesions characterized by persistent restricted diffusion during treatment with bevacizumab. The purpose of the current study was to characterize the evolution of these lesions and to determine their relationship to patient outcome.

Purpose: To compare ''standardization,'' ''Gaussian normalization,'' and ''Z-score normalization'' intensity transformation techniques in dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) estimates of cerebral blood volume (CBV) in human gliomas. DSC-MRI is a well-established biomarker for CBV in brain tumors; however, DSC-MRI estimates of CBV are semiquantitative. The use of image intensity transformation algorithms provides a mechanism for obtaining quantitatively similar CBV maps with the same intensity scaling. Materials and Methods:The coefficient of variance (CV) in normal-appearing white matter and relative contrast between tumor regions and normal tissue was compared between the three CBV transformations across five different MR scanners in 96 patients with gliomas. Results:The results suggest all normalization techniques improved variability and relative tumor contrast of CBV measurements compared with nonnormalized CBV maps. The results suggest Gaussian normalization of CBV maps provided slightly lower CV in normal white matter and provided slightly higher tumor contrast for glioblastomas (WHO grade IV) compared with other techniques. Conclusion:The results suggest Gaussian normalization of leakage-corrected CBV maps may be the best choice for image intensity correction for use in large-scale, multicenter clinical trials where MR scanners and protocols vary widely due to ease of implementation, lowest variability, and highest tumor to normal tissue contrast.

Relative asymmetry is more important than absolute size for determining nerve canal/foramen abnormality. These normative data may be useful adjuncts to subjective assessments of nerve canal/foramen size when using skull base CT to identify tumor.

External carotid artery (ECA) pseudoaneurysm is a known complication of treatment for head and neck cancer. We report a case of facial artery pseudoaneurysm arising after irradiation and salvage surgery for advanced tonsillar cancer, that was treated with endovascular embolization. The case was complicated by delayed transcutaneous extrusion of embolization coils through the skin of the anterior neck. We review the literature for related cases of coil extrusion in the head and neck, and discuss the implications for pseudoaneurysm surveillance.