Experimental measurements of the scatter reduction obtained in mammography with a scanning multiple slit assembly

A nonconventional and sensitive method of measuring scatter is described. The method was employed to quantitate the scatter imaged in mammography with a conventional unit, a unit equipped with a grid, and a unit equipped with a scanning multiple slit assembly (SMSA). The results indicate that the grid technique significantly reduces the scatter imaged, while the SMSA virtually eliminates it. The resultant increase in large area contrast is readily apparent on radiographs with greater improvement obtained with the SMSA than with the grid. The effect of the increase in contrast on small detail visibility was assessed with a phantom having simulated fibrils and calcifications. Significantly more fibril and calcification detail was visible with the grid and SMSA technique than with the conventional technique. The detail visible with the grid and SMSA technique was comparable, and the lack of better performance by the SMSA unit is attributed to its poorer MTF.