LIMITED VALUE OF SCINTIMAMMOGRAPHY AND CONTRAST-ENHANCED MRI IN THE EVALUATION OF MICROCALCIFICATION DETECTED BY MAMMOGRAPHY

The aim of this study was to evaluate whether scintimammography using Tc-99(m)-sestamibi or contrast-enhanced magnetic resonance imaging (MR I) can improve the specificity of mammography for the differentiation of benign and malignant breast microcalcification. From 156 consecutiv e patients studied with SMM, 44 patients with microcalcification on ma mmograms were selected for this study. Forty patients in this group al so had contrast-enhanced MRI of the breast. The intensity and patterns of sestamibi uptake for scintimammography and contrast enhancement fo r MRI were visually determined and graded on a 5-point scale for malig nancy. The results of both techniques were compared and correlated wit h final histopathologic diagnoses. The sensitivity and specificity of scintimammography were 63% and 85% respectively, if only those cases c lassified as probable or definite malignancy were considered positive. If indeterminate findings were also considered positive, the sensitiv ity and specificity of scintimammography were 79% and 80% respectively . Using the latter classification for MRI revealed a comparable sensit ivity of 82% but a markedly lower specificity of 56%. Excluding indete rminate findings from the group of positive MRI diagnoses resulted in a specificity of 94% and a sensitivity of 64%. In conclusion, scintima mmography of the breast had a comparable sensitivity but a higher spec ificity than MRI. The sensitivity of both techniques, however, is prob ably too low for routine use in the evaluation of microcalcification d etected by mammography.