Neuroimaging clinics of North America
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The central skull base (CSB) constitutes a frontier between the extracranial head and neck and the middle cranial fossa. The anatomy of this region is complex, containing most of the bony foramina and canals of the skull base traversed by several neurovascular structures that can act as routes of spread for pathologic processes. ⋯ Crosssectional imaging is indispensable in the diagnosis, treatment planning, and follow-up of patients with CSB lesions. This review focuses on a systematic approach to this region based on an anatomic division that takes into account the major tissue constituents of the CSB.
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This article describes the rationale, indications, and modality for intraoperative brain mapping for safe and effective surgical removal of tumors located within functional brain areas.
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Neuroimaging Clin. N. Am. · Nov 2009
Presurgical mapping of verbal language in brain tumors with functional MR imaging and MR tractography.
Functional magnetic resonance (fMR) imaging and diffusion MR tractography have emerged as valuable tools in the evaluation of verbal language in brain tumor patients, and have changed the way neurosurgeons look at patients with a mass in the dominant hemisphere. The techniques have obtained recognition as valuable presurgical clinical tools in the determination of hemispheric dominance and in the selection of candidates who may benefit from awake craniotomy. In the near future fMRI and diffusion MR Tractography may contribute to elucidate mechanisms of brain plasticity and may provide predictors of favorable postoperative clinical outcome. The functional anatomy of the language network and the role of fMR imaging and diffusion MR tractography in the evaluation of patients with a brain tumor are the focus of this article.
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Neuroimaging Clin. N. Am. · Nov 2009
Advanced MRI: translation from animal to human in brain tumor research.
Advanced magnetic resonance imaging (MRI) techniques, such as magnetic resonance spectroscopy, diffusion MRI, and perfusion MRI, allow for a diverse range of multidimensional information regarding brain tumor physiology to be obtained in addition to the traditional anatomic images. Although it is well documented that MRI of rodent brain tumor models plays an important role in the basic research and drug discovery process of new brain tumor therapies, the role that animal models have played in translating these methodologies is rarely discussed in such articles. ⋯ This is despite that the use of rodent cancer models to test advanced MRI techniques predates and was integral to the development of clinical MRI. This article highlights just how integral preclinical imaging is to the discovery, development, and validation of advanced MRI techniques for imaging brain neoplasms.
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Despite the recognized limitations of (18)Fluorodeoxyglucose positron emission tomography (FDG-PET) in brain tumor imaging due to the high background of normal gray matter, this imaging modality provides critical information for the management of patients with cerebral neoplasms with regard to the following aspects: (1) providing a global picture of the tumor and thus guiding the appropriate site for stereotactic biopsy, and thereby enhancing its accuracy and reducing the number of biopsy samples; and (2) prediction of biologic behavior and aggressiveness of the tumor, thereby aiding in prognosis. Another area, which has been investigated extensively, includes differentiating recurrent tumor from treatment-related changes (eg, radiation necrosis and postsurgical changes). Furthermore, FDG-PET has demonstrated its usefulness in differentiating lymphoma from toxoplasmosis in patients with acquired immune deficiency syndrome with great accuracy, and is used as the investigation of choice in this setting. ⋯ The value of hypoxia imaging tracers (such as fluoromisonidazole or more recently EF5) is substantial in radiotherapy planning and predicting treatment response. In addition, they may play an important role in the future in directing and monitoring targeted hypoxic therapy for tumors with hypoxia. Development of optimal image segmentation strategy with novel PET tracers and multimodality imaging is an approach that deserves mention in the era of intensity modulated radiotherapy, and which is likely to have important clinical and research applications in radiotherapy planning in patients with brain tumor.