Introduction: The number of exposures performed on an imaging plate has a long term impact on the plate itself and lowers its sensitivity. By measuring the exposure index and the dose area product we can define how much ionizing radiation reaches the imaging plate and the patient. If we want to keep the exposure index between the old and the new plates comparable, we have to adjust the exposure parameters correctly. Purpose: The purpose of the diploma work is to assess how the number of exposures affects imaging plates for computed radiography by comparing old and new imaging plates. Methods: To write the diploma work we used the descriptive method by overviewing relevant literature, and the experimental method. This included gathering measurements, which we used to compare the old and the new imaging plates and define what impact this has on the radiation dose for the imaging plate and the dose for the patient. We adjusted the parameters to keep the exposure index comparable. Results: The research showed that the exposure index is much higher when we use a new imaging plate. That is why we have to adjust the exposure parameters. When the parameters used on the new imaging plates are comparable to the parameters used on the old imaging plates, the patient radiation dose is much lower on the new imaging plates. Discussion and conclusion: The results evidently show statistically defined differences in doses on the plate and for the patient comparing old and new imaging plates. Moreover, we can see that the number of exposures performed on an imaging plate in the time of use, affects the quality of the images.
|
