Proposed Guidelines for Image Quality Optimization in Chest PA X-Ray Examinations In Bangladesh

The common practice for chest PA examinations in Bangladesh employ low kV imaging. This practice involves low-contrast images and requires much larger radiation doses than those associated with higher beam energy. Thus, we propose a model relating the change of Entrance Surface Dose (ESD) in response to changes in beam energy, in accordance with European standards for diagnostic radiographic chest imaging to find the optimal ESD corresponding to values of kVp used in Bangladeshi hospitals. Results show that in order to maintain the standards of Quality for Diagnostic Radiographic Image every 10kVp increase in beam energy must be followed by a decrease of 8/6 in ESD that corresponds to a reduction of 15% in the equivalent dose. Hence, the range of optimal ESD accounting for the kVps practiced for chest PA examinations is 5.6-10 mGy, which represents a factor of 35 above the recommended ESD. Finally we investigate the effect of Body Mass Index (BMI) on optimal ESD for overweighed Bangladeshi patients. We find that, for each additional 1kg, the ESD must increase 18% in order to maintain standards for chest PA x-ray image.