Evaluation of magnification and paddle compression techniques in the assessment of mammographic screening detected abnormalities.

Between February 1988 and December 1989, 8.6% of all women who presented to the South East London Breast Screening Centre for mammography were recalled for assessment. Magnification or paddle compression techniques were used in the assessment of 39% of these patients. The aim of the study was to evaluate the improvement in mammographic specificity provided by these 'special views'. Three hundred and thirty cases were reviewed. The basic mammograms were assessed both alone and together with the special views, and the mammographic findings were scored according to the index of suspicion for malignancy. Special views were felt to be helpful when they led to an increase in mammographic specificity. It was found that special views increased mammographic specificity in 50.8% of cases. Sixteen 'equivocal' diagnoses became 'normal' or 'benign' and 15 of these patients avoided surgical biopsy. Twelve 'equivocal' diagnoses became 'malignant', which helped surgical planning, and in all 12 cases, histology confirmed the diagnosis of malignancy. It is felt that 'special views' are necessary for the complete mammographic assessment of many screen-detected abnormalities.