Image plate systems differ in physical performance

Objective. The purpose of this study was to compare 2 storage phosphor image plate systems, the Digora and the DenOptix, with respect to physical performance. Study design. The 2 systems were tested both with and without use of their default settings through physical and psychophysical measurements. A homogeneous 10-mm-thick aluminum block, a 10-mm-thick aluminum block with a pattern of holes varying in diameter and depth, and a resolving power target were used as rest phantoms. The image plates were exposed at 50 kV and 8 mA with a focus-sensor distance of 30 cm and exposure times ranging from 10 to 3200 ms. Measurements of large area transfer function, gray level variations, perceptibility, contrast resolution, exposure range, and modulation transfer function were performed. Results, When the two systems were used at their default settings, the DenOptix had a better dose response, a higher contrast index, and a higher modulation transfer function (MTF) than the Digora; however, the DenOptix also had higher noise than the Digora at lower exposures. Conclusions. When image enhancement algorithms were applied with the Digora system, performance similar to that of the DenOptix could be obtained.