MTF Optimization in Digital Dental X-ray Systems
  In this work, we have studied the MTF optimisation relative to the detector aperture of four digital dental X-ray image systems: 1) Digora and Denoptix systems, based on PSPL detectors; 2) CDR and Sens-A-Ray 2000, based on CCD detectors. The MTF was evaluated by ERF method and linearized as a Gaussian process. The CCD based systems presented Gaussian characteristics. The PSPL based systems presented a composition of two Gaussian processes. We conclude that one process is due to the laser and stimulated light scattering inside the PSPL plate and the other is due to the laser beam focal aperture. Matching focal aperture to laser scattering allows the optimization of the PSPL systems resolution. An optimal pixel width found to be 62 um. 
Eduardo Tavares Costa and Jorge Andre Girao Albuquerque (CEB and   DEB/FEEC/Unicamp, Campinas, SP, Brazil)