Combination of multiple pencil-beam imaging to computed storage phosphor radiography: a new method

Computed radiography (CR) with storage phosphors offers a wide dynamic range and improved sensitivity compared to film-screen technology. CR was combined in this study with a prototype multiple pencil-beam (MPB) imaging device which has been shown to be very effective in scatter reduction. The combination was analyzed and compared to the standard technique of grid screening in two ways: a free-response ROC (FROC) analysis was first performed followed by a blinded test arrangement for visual analysis of image quality in a series of computed radiography of the lumbar spine by both the MPB and grid modalities. The results of the FROC study showed a statistically significant (P less than or equal to 0.01) improvement in signal detection. The MPB-CR images of the lumbar spine had more contrast but also a slightly mottled or grainy appearance. Image quality was found good but contrast processing was criticized because it seemed to result in a too steep display of contrast in MPB imaging. This should be avoidable by changing the image processing parameters.