Assessments of the quality of radiographic imaging in computed radiography image

The aim of the study is to evaluate the quality of radiographic imaging through the steps in computed radiography (CR) image acquisition. The insights can be gained for administrators to better scheduling curriculum development of post-graduated year (PGY) training program and clinic competency assessment of radiologists, which in turn may improve the quality of medical care. The aim of the study is to examine what factors having influence on radiographic imaging quality, and the study are evaluated as follows: (i) exposure factors (45, 50, 55, 60, 65, 70 KVp and 5.6, 6.3, 8, 10, 12.5, 14.0, 16.0 mAs, respectively) (ii) radiographic positioning technique (iii) the ALARA principle (exposure to patient as low as reasonably achievable), (iv) x-ray quality (the measurement of half-value layer by using different thickness of copper foil (0.1mm -1.0mm). The optimal exposure factor of 55 KVp, 8 mAs for skull AP axial view has better image quality and the lowest surface dose rate of 0.41μC. The optimal exposure factor of 60 KVp, 5.6 mAs for skull lateral view has better image quality and the lowest surface dose rate of 0.62μC. From the results of radiographic imaging, the exposure factors of KVp and mAs may be strongly related to the quality of the image. The study shows that KVp controls the image constrast while mAs controls the optical density. We measured the relationship of dose intensity against distance by using a current-type DC ion chamber. It seemed that the dose intensity of x-ray has an inverse square relationship with distance from the source to the central line of the ion chamber. The half-value layer (HVL) of copper is about 0.221 mm. The results meet the requirements of clinical digital medical image processes. It also confirms the effectiveness of the x-ray quality supplied by hanging-type diagnostic x-ray machines.