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Updated: Aug 24, 2026
X-ray Dose Reduction through Adaptive Exposure in Fluoroscopic Imaging
Published on: September 11, 2011
Comparison of an automatic versus a semiautomatic mode for gray-scale adaptation for digital chest radiography
Johannes Sailer1, Mathias Prokop, Ulrich Neitzel
1Department of Radiology, University of Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria. johannes.sailer@univie.ac.at
Purpose:
To compare image quality of digital chest radiographs using 2 modes of gradation adjustment.
Methods:
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.
Results:
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.
Conclusion:
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.
