The study of kilovoltage peak selection for chest x-ray examination in Samutprakarn province

Abstract

Peak kilovoltage (kVp) is one of the exposure techniques used to control an image quality of chest x-ray (CXR) and an exposure to patient. In the past, the kVp was strictly selected based on screen-film characteristics to maintain a good radiographic quality. Digital imaging system can provide wider range of kVp selection while maintaining adjustable display image. This would encourage new technique such as high kVp CXR which provides better lung parenchyma and mediastinum seen. Samutprakarn province is an important industrial area that usually require CXR for health screening of the staff. We have noticed that kVp for CXR of each hospital did not similar event in nearby area. This study aimed to survey the kVp for CXR and factors related to these kVp selection from 21 hospitals in Samutprakarn province using the questionnaire. The results showed the mode kVp was 85 and the average kVp was 87.85 ± 13.83. The highest satisfactions score was 4.19 ± 0.68 (Image detail). The lowest satisfactions score was 2.42 ± 1.16 (screen-films technique adopting). There was significant correlation between body part thickness and penetrating power (r = 0.615, p < 0.05) and image detail. There was significant correlation between detectability of radiographic pathology (r = 0.612, p < 0.05). The high tube voltage range between 110-110 kVp was selected by the radiologist while the low range between 70 – 90 kVp was selected among radiographers. The mode kVp (85) in this study was not high kVp technique. The wide kVp range of 70 – 120 had shown the variation of kVp selection for CXR in Samutprakarn hospital. Further study should include patient exposure and clinical information.