The Value Of Strain Ratio By Ultrasonic Elastography In Differentiating Benign And Malignant Breast Lesions

Objective This study was performed to evaluate the differentialdiagnosis value of the benign and the malignant breast tumor by measuringthe entire strain ratio (ESR) and maximum strain ratio (max-SR) with thereal-time tissue elastography (RTE) compared with the conventionalultrasound(CUS，including B-mode sonography、colour Doppler flow imagingand Doppler spectrum).Methods From September2012to May2013,137femal patients with207breast lesions were enrolled，all of them were inpatients of our hospital toreceive operations. Each of them received B-mode sonography, Dopplersonography and the real-time tissue elastography （RTE）, to get the relativestiffness of lesion by measuring the entire strain ratio (ESR) and themaximum strain ratio (max-SR) of breast lesion to the same level breast tissueunder good strain images. By comparing with the results of pathologicaldiagnosis and with it as the gold standard, the cut-off point for the ESR andthe max-SR were got using the receiver operating characteristic curve(ROC).Results The mean ESR value of malignant lesions was significantlygreater than that of benign lesions (5.36±3.45,1.49±0.72, P <0.01）,respectively. The mean max-SR value of malignant lesions was significantlygreater than that of benign lesions too (2.42±1.13,8.44±4.49, P <0.01),respectively. The area under the curve of ESR and max-SR were0.969and0.965, respectively. If we chose the ESR≥3.105as the cut-off point for malignancy and＜3.105for the benignity, the sensitivity, the specificity,the accuracy, the positive and the negative predictive values were88.5%,97.9%,94.7%,94.7%,95.3%，respectively. If we chose the max-SR≥4.335as the cut-off point for malignancy and＜4.335for the benignity, thesensitivity, the specificity, the accuracy, the positive and the negativepredictive values were90.2%,92.5%,91.8%,83.3%,95.7%，respectively.The sensitivity, the specificity, the accuracy, the positive and the negativepredictive values of conventional sonography were96.7%,87.0%,89.9%,75.6%,98.4%. The Results showed that the accuracy of the three methodshave no obvious statistical significance, but the ESR had the better specificityand positive predictive value than that of conventional ultrasound, thedifference was statistically significant.Conclusions ESR with elastography represents a high clinical valuefor differentiation of benign and malignant breast tumors. The specificity、the positive predicitive value are higher than the conventional sonography, thediagnostic performance of breast masses as benign or malignant is notsignificantly improved with max-SR compared with ESR, but for theheterogeneity tumor, max-SR with elastography can reflect the stiffness ofbreast lesions more objectively.