1. A method for obtaining data, said method comprising: scanning at least one of a head of a patient and a neck of the patient with a Multi-Energy Computed Tomography (MECT) system, the MECT including an x-ray source rotatable about the patient, the MECT configured to be responsive to different x-ray spectra associated with Compton scatter and photoelectric effect and within an energy region associated with medical computed tomography (CT); acquiring, from said scanning, first image data including attenuations from a Compton process and second image data including attenuations from a photoelectric process; and representing a material within the acquired image data using at least one of a density of a first reference material and a density of a second reference material.