Evaluation of chest and abdominal exposure dose appropriate for a digital image reader system incorporating a columnar-crystal structured phosphor plate and a contrast-detail phantom.

We evaluated a newly developed digital image reader incorporating a columnar-crystal structured phosphor plate (CPP) to determine its effectiveness for chest and abdominal exposures by assessing contrast-detail (C-D) curves and image quality figure values obtained from a C-D phantom. With the help of five radiologic technologists with 5 years or more of experience in the interpretation of plain radiographs, we assessed chest and abdominal radiographic films that had undergone image processing. The exposure dose required for obtaining the same image quality under chest exposure conditions (110 kV) was 66% of that necessary for a conventionally used computed radiography system incorporating a powder phosphor plate, whereas the percentage under abdominal exposure conditions (85 kV) was 82%. The rate of dose reduction varied depending on the anatomic region radiographed, the exposure conditions applied, and the method of image processing employed. Because the CPP has a higher X-ray detection efficiency than the hitherto-used powder phosphor plate, its use has to potential to reduce the patients' radiation exposure dose.