The use of conventional and advanced magnetic resonance techniques in the assessment of primary brain tumours

The aim of the work described in this thesis was to investigate the value of conventional, perfusion- and diffusion-weighted magnetic resonance imaging (MRI) in patients with histology-proven low-grade gliomas (LGG), and the potential role of these methods in the management of patients with these brain tumours. Thirty-six patients were studied at the National Hospital for Neurology and Neurosurgery using conventional, perfusion-weighted and diffusion-weighted MRI at study entry and 6 monthly intervals thereafter. At each visit, tumour volume, maximum rCBV and ADC histogram measures were calculated. This is a unique cohort, as patients were treatment free until malignant transformation was diagnosed, which translates the natural history of these brain tumours. It is unlikely to find such a specific cohort as most of the patients receive treatment after the initial diagnosis of low grade gliomas. Chapters 1 and 2 of this thesis describe the theoretical basis of the MRI techniques used, and summarise the natural history and imaging aspects of cerebral gliomas. Chapter 3 describes a methodological study relating to tumour perfusion measurement: since the inclusion or exclusion of intratumoural vessels may influence the quantification of relative cerebral blood volume (rCBV), a study was conducted to choose the best ROI placement technique to be used for the rCBV measurements included in this thesis. It was shown that only the approach which excluded intratumoural vessels demonstrated a significant association between rCBV values and tumour subtypes (astrocytomas, oligodendrogliomas and oligoastrocytomas) and therefore this technique was used in all subsequent rCBV measurements

Método de diseño de redes de medida de contaminantes atmosféricos

Se presenta un método de diseño de redes de medida de contaminantes atmosféricos, Útil para realizar Estudios de Impacto Ambiental. Esta técnica conduce a una red óptima, en el sentido de que proporciona la mayor información posible utilizando el mínimo número de dispositivos de medida. En el diseño se utiliza la técnica de Análisis de Correlación Espacial, para comparar la información contenida en las posibles estaciones de medida que pueden pertenecer a la red, y el concepto de Potencial de Violación, para tener en cuenta el número de ocasiones que se detectan en que se superan los valores de inmisión permitidos por la ley. Como ilustración del método, se diseña una red de medida de contaminantes atmosféricos para realizar el Estudio del Impacto Ambiental producido por una Planta de Procesado de Potasio.Peer Reviewe

Método de diseño de redes de medida de contaminantes atmosféricos

Se presenta un método de diseño de redes de medida de contaminantes atmosféricos, Útil para realizar Estudios de Impacto Ambiental. Esta técnica conduce a una red óptima, en el sentido de que proporciona la mayor información posible utilizando el mínimo número de dispositivos de medida. En el diseño se utiliza la técnica de Análisis de Correlación Espacial, para comparar la información contenida en las posibles estaciones de medida que pueden pertenecer a la red, y el concepto de Potencial de Violación, para tener en cuenta el número de ocasiones que se detectan en que se superan los valores de inmisión permitidos por la ley. Como ilustración del método, se diseña una red de medida de contaminantes atmosféricos para realizar el Estudio del Impacto Ambiental producido por una Planta de Procesado de Potasio.Peer Reviewe

A generative approach for image-based modeling of tumor growth

22nd International Conference, IPMI 2011, Kloster Irsee, Germany, July 3-8, 2011. ProceedingsExtensive imaging is routinely used in brain tumor patients to monitor the state of the disease and to evaluate therapeutic options. A large number of multi-modal and multi-temporal image volumes is acquired in standard clinical cases, requiring new approaches for comprehensive integration of information from different image sources and different time points. In this work we propose a joint generative model of tumor growth and of image observation that naturally handles multi-modal and longitudinal data. We use the model for analyzing imaging data in patients with glioma. The tumor growth model is based on a reaction-diffusion framework. Model personalization relies only on a forward model for the growth process and on image likelihood. We take advantage of an adaptive sparse grid approximation for efficient inference via Markov Chain Monte Carlo sampling. The approach can be used for integrating information from different multi-modal imaging protocols and can easily be adapted to other tumor growth models.German Academy of Sciences Leopoldina (Fellowship Programme LPDS 2009-10)Academy of Finland (133611)National Institutes of Health (U.S.) (NIBIB NAMIC U54-EB005149)National Institutes of Health (U.S.) (NCRR NAC P41- RR13218)National Institutes of Health (U.S.) (NINDS R01-NS051826)National Institutes of Health (U.S.) (NIH R01-NS052585)National Institutes of Health (U.S.) (NIH R01-EB006758)National Institutes of Health (U.S.) (NIH R01-EB009051)National Institutes of Health (U.S.) (NIH P41-RR014075)National Science Foundation (U.S.) (CAREER Award 0642971

Advances in MRI Assessment of Gliomas and Response to Anti-VEGF Therapy

Bevacizumab is thought to normalize tumor vasculature and restore the blood–brain barrier, decreasing enhancement and peritumoral edema. Conventional measurements of tumor response rely upon dimensions of enhancing tumor. After bevacizumab treatment, glioblastomas are more prone to progress as nonenhancing tumor. The RANO (Response Assessment in Neuro-Oncology) criteria for glioma response use fluid-attenuated inversion recovery (FLAIR)/T2 hyperintensity as a surrogate for nonenhancing tumor; however, nonenhancing tumor can be difficult to differentiate from other causes of FLAIR/T2 hyperintensity (eg, radiation-induced gliosis). Due to these difficulties, recent efforts have been directed toward identifying new biomarkers that either predict treatment response or accurately measure response of both enhancing and nonenhancing tumor shortly after treatment initiation. This will allow for earlier treatment decisions, saving patients from the adverse effects of ineffective therapies while allowing them to try alternative therapies sooner. An active area of research is the use of physiologic imaging, which can potentially detect treatment effects before changes in tumor size are evident

Management of Low-Grade Glioma

The optimal management of patients with low-grade glioma (LGG) is controversial. The controversy largely stems from the lack of well-designed clinical trials with adequate follow-up to account for the relatively long progression-free survival and overall survival of patients with LGG. Nonetheless, the literature increasingly suggests that expectant management is no longer optimal. Rather, there is mounting evidence supporting active management including consideration of surgical resection, radiotherapy, chemotherapy, molecular and histopathologic characterization, and use of modern imaging techniques for monitoring and prognostication. In particular, there is growing evidence favoring extensive surgical resection and increasing interest in the role of chemotherapy (especially temozolomide) in the management of these tumors. In this review, we critically analyze emerging trends in the literature with respect to management of LGG, with particular emphasis on reports published during the past year

Padres y maestros

Se describen las principales reformas que introduce la Ley 15/2005, de 8 de julio que modifica el Código Civil y la Ley de Enjuiciamiento Civil en materia de separación y divorcio. Se centra en la opción que introduce dicha ley de solicitar la custodia compartida y se analizan sus ventajas e inconvenientes.GaliciaMadrid (Comunidad Autónoma). Servicio de Formación del Profesorado. CRIF Las Acacias; Calle General Ricardos, 179; 28025 Madrid; Tel. +34915250893; Fax +34914660991; [email protected]

Método de diseño de redes de medida de contaminantes atmosféricos

Se presenta un método de diseño de redes de medida de contaminantes atmosféricos, Útil para realizar Estudios de Impacto Ambiental. Esta técnica conduce a una red óptima, en el sentido de que proporciona la mayor información posible utilizando el mínimo número de dispositivos de medida. En el diseño se utiliza la técnica de Análisis de Correlación Espacial, para comparar la información contenida en las posibles estaciones de medida que pueden pertenecer a la red, y el concepto de Potencial de Violación, para tener en cuenta el número de ocasiones que se detectan en que se superan los valores de inmisión permitidos por la ley. Como ilustración del método, se diseña una red de medida de contaminantes atmosféricos para realizar el Estudio del Impacto Ambiental producido por una Planta de Procesado de Potasio.Peer Reviewe