The determination of scattered radiation from intraoral x-ray examinations and its projected effects on image signal-to-noise ratio.

Abstract

Scatter functions and relative depth-dose are computed for a variety of X-ray spectra and exposure geometries of dental interest. The method takes into account the attenuation produced by the lead-foil backing in intraoral film packets and makes use of an analytical model to compute the zero-area depth-dose based on known spectra and attenuation coefficients.The resulting data show that the relative amount of scatter at the film plane for a fixed exposure at the tissue surface is significant and approximates half the dose produced by the primary beam neasured at the same depth. The foil backing reduces scattered radiation reaching the film plane by an amount which is significantly influenced by the energy spectrum of the primary beam.Signal-to-noise ratios per unit area estimated from the experimental data for non-screen film show that the parameters controlled in this investigation have a relatively small but statistically significant effect on the information carrying capacity of the radiographic system.