Optimization of the Exposure Techniques for Digital Radiography in Phantom
Keywords:
Exposure Technique, Exposure Index:, Deviation Index:DI, Target Exposure Index:EIT, Entrance Surface Air Kerma:ESAKAbstract
Background: The factor of radiography is an exposure technique that relates to the kilovoltage peak (kVp) and milliampere seconds (mAs). In digital radiography, it is difficult to evaluate if the exposure technique is appropriate. In addition to considering the exposure index (EI) and deviation index(DI), which is an indication of the quality of digital radiography.
Objective: To set the exposure technique for appropriate digital radiography.
Method: This was the experimental study, by taking a radiography in Helios QA phantom. Analysis the relationship of exposure techniques with the exposure index and deviation index were performed. The study used exposure technique associated at 80 kVp and target exposure index (EIT) 400 with adjusted mAs at 4-16 mAs, the amount of entrance surface air kerma was calculated from the setting of exposure techniques.
Results: The appropriated exposure technique is the 300–600 of exposure index and the deviation index of ± 2 is 80 kVp 6.3-10 mAs.The amount of entrance surface air kerma receive is 0.44-0.70 mGy, and the optimized exposure technique for digital radiography was at 80 kVp 7.1 mAs, when set EIT400.
Conclusion: Optimization of the exposure techniques for digital radiography can be analyzed from the exposure index that is equal to or close to the specified target exposure index (EIT) and the deviation index(DI), that is equal to 0 or the closest. Knowing the entrance surface air kerma will help to adjust the exposure technique an reduce the radiation dose to the patient.
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