DO MAMMOGRAPHY, SONOGRAPHY, AND MR MAMMOGRAPHY HAVE A DIAGNOSTIC BENEFIT COMPARED WITH MAMMOGRAPHY AND SONOGRAPHY

OBJECTIVE. The purpose of our study was to assess the added value of M R mammography, mammography, and sonography compared with mammography a nd sonography in diagnostic evaluation of the breast. MATERIALS AND ME THODS. We evaluated reports of MR mammography, conventional mammograph y, and sonography of the breast in 89 patients who had been referred f or surgical biopsy, The dynamic MR mammography examinations were obtai ned on a 1.0-T MR imager using a double-breast coil and a three-dimens ional axial fast low-angle shot sequence. Each type of study was inter preted by a different observer. All mammograms and sonograms were avai lable to all observers. Without knowledge of biopsy results, observers classified mammograms and sonograms (which we call the standard metho d) as well as mammograms, sonograms, and MR mammograms (which we call the combined method). Classifications were on a per-breast basis: no d isease; probably a benign or malignant lesion; and most likely a benig n or malignant lesion. A classification of no disease or most likely a benign or malignant lesion was considered to represent a high confide nce of the observer in the diagnosis. RESULTS. Of 98 breasts evaluated with the standard method, observer confidence was high for 44% of all malignant lesions versus 86% with the combined method. The highest sp ecificity (92%) was achieved by interpretation of the standard method (combined method; 64%). The highest sensitivity (95%) was achieved by interpretation of the combined method (standard method, 83%). Overall accuracy was 87% for the standard method and 83% for the combined meth od. In separate analyses of nonpalpable and palpable lesions, the comb ined method achieved an accuracy of 74% for nonpalpable lesions and 88 % for palpable lesions. The standard method achieved an accuracy of 85 % for nonpalpable lesions and 88% for palpable lesions. CONCLUSION. MR mammography as an adjunct to mammography and sonography reveals breas t cancer with a higher confidence and sensitivity than do mammography and sonography only. The combined method can be recommended if the gre atest possible sensitivity or negative predictive value is wanted. How ever, the combined method is not useful for screening or workup of sus picious lesions because of its lower specificity and accuracy.