Comparison of an automatic versus a semiautomatic mode for gray-scale adaptation for digital chest radiography.

Abstract

To compare image quality of digital chest radiographs using 2 modes of gradation adjustment. We compared image quality and visualization of anatomic landmarks of 50 chest radiographs after digital processing using a semiautomatic mode with a fixed gamma of 2.6 and an automatic mode with individual gamma adaptation. The mean gamma was significantly higher (P < 0.001) with the automatic mode (3.0 vs. 2.6, respectively). Patient constitution had no impact on the automatically adapted gamma for PA but showed a significant correlation (P < 0.001) for lateral images. For PA, there was a preference (P < 0.016) of the semiautomatic mode in heavier patients whereas no difference was seen in slim patients. For the lateral projection, there was a general preference (P = 0.001) of the automatic mode. For PA radiographs, the semiautomatic mode provides superior results for heavier patients without compromising the quality in slim patients. For lateral radiographs, the automatic mode provides generally superior results.