Value Of MR Rout-scanning, Dynamic Contrast-enhanced MRI And Diffusion-weighted MR Imaging For The Diagnosis Of Breast Leision.

Objective: to approach the value of MRI rout-scanning , dynamic contrast-enhanced MRI and diffusion-weighted MR imaging for the diagnosis of breast leision.Methods: we analyzed forty-seven leisions from forty-five patients who were operated and acquired with histopathological demonstration, of which thirty-one were malignant and sixteen were benign All lesions were examined with MRI plain scan, dynamic contrast-enhanced MRI and diffusion-weighted MR imaging. The sequences used were T2WI, T1WI, fat-suppression T2WI, fat-suppression T1WI, three-dimensional-fast low-angle shot and SE-EPI, b=1000s/mm². The images were reviewed and made consensus on the shape, contour and the type of time-signal intensity curve(TIC) by two radiologists at workstation. We calculated the enhancement rate 1 minut after ejection of GD-DTPA(â–³SI). The suspicious malignant aspect of morphology, the type of TIC andâ–³SI was given a point. The leisions were classified as malignant, suspicious or benign according the score summed up. We measured apparent diffusion coefficient(ADC) of the leision using region of interest(ROI) technique correlated with the location of enhanced lesion. Threshold of ADC for diagnosis was acquired by ROC analysis , and lesions were classified as benign and malignant. The validities of dynamic contrast-enhanced imaging, ADC, and combination of the two methods were evaluated.Result: (1) The sensitivity, spectivity, and accuracy of MRI rout-scanning were 74.2%(23/31), 50%(8/16) and 66%(31/47). (2) The sensiticity, spectivity, and accuracy of dynamic contrast-enhanced imaging were 87.1%(27/31), 62.5%(10/16) and 78.7%(37/47). (3) The Threshold of ADC for diagnosis was 1.2×10^-3mm²/s by ROC analysis. The sensitivity, respectivity and accuracy of ADC were 93.6%(29/31), 75%(12/16) and 87.2%(41/47). (4) The sensitivity, respectivity and accuracy of combination of dynamic contrast-enhanced MRI and DWI-ADC were 83.9%(26/31), 87.5%(14/16) and 85.1%(40/47). Four benign leisions diagnosed as suspicious malignance on dynamic contrast-enhanced MRI were benign according to combination of dynamic MRI and ADC. Six of malignant leisions which were suspicious in dynamic contrast-enhanced MRI, definite malignant diagnosis due to combination with ADC.Conclusion: (1) The leision which has speculated margin, skin thickening and edema, nodes with a diameter of more than 1cm can be diagnosed by MR rout-scanning directly. (2) The typically malignant signs include irregular or speculated margin, warsh-out curve, rimlike enhancement, heterogeneous internal enhancement and enhancing internal septa, skin thickening and edema, nodes with a diameter of more than 1 cm. The typically benign signs include smooth and lobulated margin, low-signal-intensity internal septa, mild regional nonmass enhancement, homogeneous enhance-ment , without enhancement and progressive enhancement curve. (3)The sensitivity and spectivity of DWI is high , it is helpful for diagnosis and can be used as a conventional sequence. The Threshold of ADC for diagnosis was 1.2×10³mm²/s by ROC analysis, the leision whose ADC≤1.2×10^-3mm²/s was malignance, and ADC＞1.2×10^-3mm²/s was benign. (4)The combination of dynamic contrast-enhanced MRI and DWI is useful to increase spectivity, and can provide valuable and affluent information for the diagnosis of those leisions suspicious in dynamic contrast-enhanced MRI.