Acoustic Radiation Force Impulse (ARFI) assessment of differential diagnosis of malignant and benign solid breast masses

Objectives To evaluate the performance of ARFI in diagnosis of solid breast tumors (BTs) by qualitative (the color-mapped pattern analysis) and quantitative (shear wave velocity measurement), then to propose the combination of ARFI and Bmode in differentiating malignant and benign breast lesions. Methods Bmode ultrasound (BUS) were performed on 162 female patients who have BTs and BUS images were classified according to the Breast Imaging-Reporting and Data System. ARFI elastography was performed using VTIQ (Siemens Acuson S2000), we evaluated the color-mapped patterns of the breast lesions and measured the shear wave velocity (at 5 points of the lesion, use the mean of SWV (m/s)). Determined diagnosis based on pathology results. Using Medcalc software to analyse and compare the ARFI mean value between the 2 groups of benign and malignant BTs. Results 162 female patients (mean age 41. 72, range 17-69 years old) who have breast tumors included 129 (79. 7%) benign lesions and 33 malignant (20. 3%). The ARFI value of breast tumor was 3. 03 (m/s), benign BT was 2. 7 (m/s) and malignant BT was 4. 81 (m/s). The ARFI cut-off value predicted malignancy was 3. 55 (m/s). Using ROC (cut-off value of 3. 55 (m/s)), the positive predictive value of 100% for malignant lesions showed a sensitivity of 90. 9% and a specificity of 93. 8%, AUC=0. 95. With t-test, there were significant statistically differences of ARFI value between 2 groups of malignant and benign breast tumors. 18 BTs were downgraded BIRADS after evaluated by VTIQ included 15 BTs BIRADS 4A->BI-RADS 3; 2 BTs BI-RADS 4B-> BI-RADS 4A, 1 BT BI-RADS 4C->BI-RADS 4B, all correlated with benign pathology results (100%). Conclusions The SWV of malignant BT increased with the cut-offvalue of 3. 55 (m/s) showed a sensitivity of 90. 9% and a specificity of 93. 8%. ARFI contributed to downgrade BI-RADS of BT, helped to select the appropriate biopsied position due to the colored-map, has utility in differentiating malignant and benign BT.