| ObjectiveTo evaluate the sensitivity, specificity, positive predictive value, negative predictive value of dynamic contrast-enhanced subtraction magnetic resonance imaging (MRI) diagnosis in non-calcified breast cancer and to compare them with thosese by mammography examination. Application of dynamic contrast-enhanced subtraction MRI in non-calcified breast cancer diagnosis has also been discussed.MethodsRetrospective analysis has been conducted with MRI and mammography examination for70 patients with confirmed breast lesions by pathology. These include 26 cases of malignant ones, for a total of 30 lesions, ages ranging from 25 to 50 years with a median age of 47 years, among all cases,27 lesions belong to invasive ductal carcinoma,3 to mucinous carcinoma; 44 cases of benign ones with a total of 50 lesions, ages ranging from 22 years to 55 years with a median age of 45 years, among all cases 30 to breast fibroma,8 to papilloma,6 to breast cysts, and 6 to breast hyperplasia. Criteria for mammography diagnosis:based on two major indicators or one major plus two minor indicators one can determine the lesion to be either benign or malignant. The main indicators were:(1) irregular or lobulated mass with fuzzy edges or glitches, having high density; (2) small focal dense shadow or structural disorder. The minor indicators were as follows: (1) significant increase in blood flow; (2) skin thickening or limitations of depression; (3) emerging unilateral nipple retraction; (4) non-symmetry of ductal thickening; (5) enlargement of internal mammary lymph nodes, or axillary lymph nodes. Comprehensive MRI diagnostic criteria:among 4 key indicators, presence of either three key indicators or two main indicators plus two secondary indicators distinguish between benign and malignant disease. Key Indicators were:(1) morphological characteristics:nodular or irregular lesions, irregular edges or burrs; (2) enhanced lesions and/or with uneven, or ring-shaped internal; (3) dynamic contrast-enhanced MRI for early rate of≥90% and/or enhanced peak appeared before 3 min; (4) type-Ⅲtime-signal intensity curve. Secondary indicators were:(1) skin thickening or localized depression; (2) emerging unilateral nipple retraction; (3) enlarement of internal mammary lymph nodes, or axillary lymph nodes. Diagnosis of breast lesions was conducted by two experienced physicians with advanced ranks. The two diagnosis and pathological analysis were then compared. In case that two physicians were not in full agreement in diagnosis, a consensus was achieved through thorough deliberations. Afterwards, the positive predictive value, negative predictive value, sensitivity and specificity for either the MRI or X-ray examinations were calculate. The Kappa values were calculated for both the MRI and the mammography approaches and comparison with pathological diagnosis were made to evalate the diagnostic values of these two methods.ResultsOf the total of 30 breast lesions, MRI detected 28 lesions; high-frequency mammography detected 23 lesions and they all share the main indicator of the fuzzy edges, higher density nodular masses; The other 7 lessions were missed because of foci of higher breast density, which leads to a false negative by the mammography method. For the 50 benign cases, MRI detected 47 lessions; high frequency mammography, on the other hand, detected 42 lesions, including 8 false positive. The reason for the false positive can be attributed to the presence of the higher density of lesions which was mistaken to be cancer.. The sensitivity of diagnostic mammography was 76.7%, specificity 84.0%, positive predictive value 74.2%, negative predictive value 85.7%. For MRI, the sensitivity was 93.3%, specificity 94.0%, positive predictive value 90.3%, negative predictive value 95.9%. Correlation of MRI and pathological diagnosis is higher than that of mammography and pathological diagnosis. The former has (Kappa value 0.775), higher than mammography(Kappa value-0.538).Conclus ionMRI has high soft tissue resolution. Through dynamic contrast-enhanced subtraction magnetic resonance imaging, could have a better result in diagnosing non-calcified breast cancer. In comparsion to mammgraphy examination, MRI correlates with pathology better. |
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