In this paper, we present a model that is used to improve the resolution of autoradiographic images. The model involves a point spread function (PSF) due to the radiated pattern of emitted photons combined with a signal-dependent noise source due to the granularity of x-ray recording film. A theoretical expression for the PSF is presented, and experimental measurements are performed using 51Cr microspheres. An iterative regularized image restoration algorithm is developed using a weighting matrix to incorporate the signal-dependent nature of the noise. Since information about the original undegraded image is not completely available, we make use of a regularization functional that is updated at each iteration to optimize the solution process. Our experimental results indicate that the resolution of autoradiographic images is improved by 43% using this algorithm.