There has been growing interest in investigating both the in vitro and in vivo detection of optical photons from a plethora of beta emitters using optical techniques. In this paper we have investigated an alpha particle induced fluorescence signal by using a commercial CCD-based small animal optical imaging system. The light emission of a 241Am source was simulated using GEANT4 and tested in different experimental conditions including the imaging of in vivo tissue. We believe that the results presented in this work can be useful to describe a possible mechanism for the in vivo detection of alpha emitters used for therapeutic purposes.
A new micro scanner CT for small animals - based on a couple of parallel quasi-monochromatic X-ray beams with different energies selectable - is under development. The aim of the study is the <i>in vivo</i> imaging of the tumor neo-angiogenesis pattern in an earlier diagnostic phase and the analysis of cancer growth and metastasis development in different tumor types on mice. As previously demonstrated<sup>1</sup>, the imaging system based on dual energy quasi- monochromatic X-ray beams provides higher sensitivity in detecting low concentrations of iodine contrast medium if compared to traditional polychromatic X-ray equipment. The <i>K-edge dual energy</i> radiology is a realistic candidate to recognize tumor neo- angiogenesis process in a very earlier stage, in which conventional systems are very poor in sensitivity. Moreover, the capability to select the energy of quasi-monochromatic beams enables the use of the <i>Multi-Energy Quasi-Monochromatic</i> technique. Tuning properly the energies allows maximizing the difference between linear absorption coefficients of healthy and pathological tissues increasing the contrast of pathologies. In order to optimize the contrast with this technique, one should know the X-ray energy regions where the absorption of healthy and pathological tissues eventually differs and that for each type of tumor under study. For this reason, the systematic X-ray characterization of many types of healthy and neoplastic human and mice tissues is in progress. The goal of this work is to obtain a catalog of liner attenuation coefficients of a variety of pathological tissues for respect to the healthy ones, finding any <i>energy windows</i> of radiological differentiation. In this paper, the theoretical methods are presented with development works and preliminary results.