Impact of the anode heel effect on image quality and effective dose for AP pelvis: a pilot study

Abstract

Purpose: Using phantoms, this pilot study aims to outline a method and generate initial data to determine whether the anode heel effect has an impact on image quality and the effective dose. Methods and Materials: A dosimetry phantom and an anthropomorphic adult phantom were positioned with feet towards anode and then cathode and exposed using 75, 80 and 85 kVp; using 18, 22 and 28 mAs. Twelve images were taken and assessed for physical and visual quality by signal to noise ratio and two alternative forced choice (2AFC) with 19 observers. Results: From 2AFC data, no significant statistical differences (p=0.811) were found in image quality. Effective dose results show no significant statistical difference (p=0.207) between the two orientations. Conclusion: No significant reduction in visual image quality or effective dose exists betweeen the two orientations. Limited data has been provided by this pilot study so the results should be treated with caution. However the method appears to generate useful information for the aim of the study and we suggest larger datasets of 2AFC and dose values should be generated to determine whether differences exist.