Effect on mammographic CR image quality of removing the anti-scatter grid

Abstract

Purpose: To investigate the effect of removing the antiscatter grid on mammographic image quality using computed radiography (CR). To compare experimental results with those recently published in a similar study using a full-field digital mammography (FFDM) detector.Method: A mammographic test phantom was used to evaluate CR image quality both with and without the antiscatter grid in operation. The test images were examined on a Philips ‘Easy Vision RAD’ workstation and were evaluated by assigning visibility scores to the various test details using a standard protocol.Results: The study shows that the visualization of subtle, low-contrast details was compromized when the grid was removed. However, the visibility of groups of micro-calcifications was largely unaffected, even when the dose was reduced.Conclusions: The reduction in detail visibility was due mainly to the contrast loss and background non-uniformity caused by scattered radiation, although this was partially offset by lower levels of quantum noise. In general, the findings did not correlate with the previously published grid-free FFDM results.