Evaluation of an anatomical filter-based exposure equalization technique in mammography

An anatomical filter-based exposure equalization technique in mammography is clinically evaluated. An observer performance comparative study, between this technique and the conventional one, is carried out on the basis of the visualization of six anatomical features situated at the breast periphery. The effect of parenchymal breast patterns and compressed breast thickness in the visualization of these features is studied. 533 craniocaudal mammograms were interpreted by two radiologists independently, using a five-point rating scale. Use of the Wilcoxon ranking test for unpaired data shows statistically highly significant improvement (p < 0.0001) in the visualization of the nipple, areola, skin and subcutaneous fat in all cases, for the equalization technique. The improvement is dependent on parenchymal breast patterns and compressed breast thickness for peripheral Cooper's ligaments and peripheral surface veins. In the case of total fatty replacement and/or thin breasts neither technique seems to be superior (p > 0.05) with respect to these two features. Clinical results indicate the value of this technique in clinical routine.