BACKGROUND AND PURPOSE External beam radiation therapy (XRT) for head and neck cancer is known to induce hypothyroidism and cause morphologic changes in the thyroid gland. This retrospective study investigates change in the size of the thyroid gland detectable by CT after XRT for laryngeal cancer. MATERIALS AND METHODS The measured width of the thyroid lobes in 61 patients treated nonsurgical...

A polychromatic X-ray beam causes the grey of the reconstructed image to depend on its position within a solid and the material being imaged. This factor makes quantitative measurements via computed tomography (CT) imaging very difficult. To obtain a narrow-energy-width reconstructed image, we propose a model to decompose multivoltage X-ray images into many narrow-energy-width X-ray images by u...

Grid is one of the most e ective new paradigms in large scale distributed computing. Only recently Petri nets have been adopted as a formal modeling framework for describing the speci c aspects of the Grid. In this paper we describe a Grid tool for High Energy Physics data analysis, and we show how modeling its architecture with nets-withinnets has led us to identify and solve a number of defec...