Effect of dose reduction in digital dental panoramic radiography on image quality

Objectives: To investigate the effect of dose reduction in digital panoramic radiography on subjective image quality and diagnostic performance. Methods: Two digital panoramic radiographs were obtained with the Orthophos DS(R) (Sirona, Bensheim, Germany) of patients (n = 100) receiving dental care. The first image was taken at the standard exposure setting. For the second image the tube current was reduced by between 48 and 53%, 63 and 69%, 75 and 80% and 80 and 81% respectively. Ten observers rated both images for 21 specific anatomical details and 30 pathological findings. Results: All radiographs taken at reduced mA levels had a significantly inferior score (P<0.01) for anatomical details. There was no difference in the scores for pathological findings. Conclusion: Radiographs obtained at reduced mA had inferior subjective image quality, but there was no difference in diagnostic performance. Thus, a reduction in tube current of approximately 50% is recommended. In certain circumstances such as follow-up radiographic examinations, a reduction of up to 65% should be considered.