title: The spatial resolution of silicon-based electron detectors in beta-autoradiography.
abstract: Thin tissue autoradiography is an imaging modality where ex-vivo tissue sections are placed in direct contact with autoradiographic film. These tissue sections contain a radiolabelled ligand bound to a specific biomolecule under study. This radioligand emits beta - or beta+ particles ionizing silver halide crystals in the film. High spatial resolution autoradiograms are obtained using low energy radioisotopes, such as (3)H where an intrinsic 0.1-1 microm spatial resolution can be achieved. Several digital alternatives have been presented over the past few years to replace conventional film but their spatial resolution has yet to equal film, although silicon-based imaging technologies have demonstrated higher sensitivity compared to conventional film. It will be shown in this work how pixel size is a critical parameter for achieving high spatial resolution for low energy uncollimated beta imaging. In this work we also examine the confounding factors impeding silicon-based technologies with respect to spatial resolution. The study considers charge diffusion in silicon and detector noise, and this is applied to a range of radioisotopes typically used in autoradiography. Finally an optimal detector geometry to obtain the best possible spatial resolution for a specific technology and a specific radioisotope is suggested.
authors.affiliation: Centre for Vision, Speech and Signal Processing, Faculty of Electronics and Physical Sciences, University of Surrey, Guildford, Surrey, GU2 7XH, UK. jcabello@ific.uv.es
authors.forename: Jorge
authors.initials: J
authors.lastname: Cabello
authors.forename: Kevin
authors.initials: K
authors.lastname: Wells
mesh_terms: D000042:Absorption; D001345:Autoradiography / Q000295:instrumentation* / Q000379:methods; D001610:Beta Particles; D003198:Computer Simulation; D004058:Diffusion; D004583:Electrons; D004867:Equipment Design; D006219:Halogens / Q000737:chemistry; D009010:Monte Carlo Method; D011868:Radioisotopes; D012680:Sensitivity and Specificity; D012825:Silicon / Q000737:chemistry*; D018030:Silver Compounds / Q000737:chemistry
chemical_list: D006219:Halogens; D011868:Radioisotopes; D018030:Silver Compounds; D012825:Silicon