First clinical experience with a full-size, flat-panel detector for imaging the peripheral skeleton.

Purpose: This investigation was intended to show that exposures of the peri pheral skeleton system can be done with half of the dose used for conventio nal screen-film systems with a full-size Csl/a-Si flat panel detector. Mate rial an Methods: 120 exposures of the wrist and 100 exposures of the ankle have been made on a full-size flat panel detector system (43x43 cm). The pa tient dose has been reduced by a factor of two compared to conventional ima ges. Five radiologists evaluated every image as a softcopy and a hardcopy i mage. For the evaluation, a variation of the Visual Grading Analysis (VGA) without reference images was used. For the determination of the patient ent rance dose, measurement of a phantom were performed. Results: A dose reduct ion of about 50% is possible with the same or even better image quality in routine diagnostics. Only 3% of the ankle and approx. 21% of the wrist expo sures required a postprocessing. Exposures with implants did not show any a rtifacts and some of the those achieved better evaluation results compared with exposures without implants. Conclusion: A halving of the patient dose is possible with acceptable results for the image quality. The effect of an improved image processing remains to be evaluated. The patient entrance do se is suitable for an evaluation of a radiographic detector and especially for a dose-referred comparison of digital X-ray units.