Characterization of intraoral digital detectors: Comparative analysis in spatial and reciprocal domains across two different beam qualities

Abstract

The transition from analog to digital systems in dental radiography is primarily driven by the technological advancements offered by digital detectors. This study evaluates the performance of three commercially available intraoral digital detectors—Eagle Digital Sensor, RVG 5200 Carestream Dental, and Schick Fona CDRelite—under two beam qualities: the standard RQA 5 quality (70 kVp, 21 mm Al) and a new proposed quality in this work (70 kVp, 12 mm Al) more applicable to dental practices. Detector air kerma (DAK) levels ranged from 10 to 500 μGy. The assessment included metrics in both spatial and reciprocal domains, measuring response linearity, noise spatial invariance, noise component analysis, Modulation Transfer Function (MTF), Normalized Noise Power Spectrum (NNPS), and Detective Quantum Efficiency (DQE). All detectors displayed linearity across beam qualities, though the fitting coefficients varied. Quantum noise was predominant across almost the entire DAK range studied, and MTF showed minimal variation across beam qualities. The spatial frequency for MTF 10 % was 11 lp/mm for the RVG 5200 and 10.5 lp/mm for the Eagle, while the Schick CDRelite reached this point at 5.5 lp/mm. In all systems, an expected decrease in NNPS values with increasing DAK was observed. The newly proposed beam quality slightly favored DQE values at comparable DAK levels. For the DQE at 5 lp/mm, the Eagle detector increased from 0.056 to 0.065, the RVG 5200 from 0.164 to 0.170, and the Schick CDRelite from 0.026 to 0.033. The optimal exposure conditions for all studied detectors were determined through DQE analysis.