Role of Ultrasound Strain Ratio Elastography in Diagnostic Breast Imaging

Aim and Objectives: 1) To establish and assess the diagnostic accuracy of the role of strain ratio elastography in characterization of breast masses, compared to conventional B mode ultrasonography. 2) To establish strain ratio cut off in differentiating between benign and malignant breast lesions. Materials and Methods: The study was conducted in our institute for a period of 6 months and included 101 female patients using inclusion and exclusion criteria. Protocol: Patients with breast mass were subjected to conventional B-mode breast ultrasonography by radial scanning pattern using very high frequency transducer (7.5-12MHz) of Hitachi Aloka arietta 70 and categorization was done according to BIRADS categories, then elastography mode was appliedto calculate the strain ratio (SR). Histopathological assessments were done. Results: Based on the ROC curve, the strain ratio cut off of 2.69 was established in differentiating benign and malignant breast lesions. The area under the curve of B mode USG based on BIRADS was 0.891, p value of 0.0005 (Statistically significant) under 95% CI. The area under the curve for strain ratio was 0.925. p value of 0.005 (statistically significant) under 95 % CI. The characterization based on BIRADS showed sensitivity of 78.1%, specificity of 100%, PPV of 100 %, NPV of 90.8% and accuracy of 93.1 %. The characterisation using strain ratio showed sensitivity of 93.8%, specificity of 91.3%, PPV 83.3%, NPV 96.9% and accuracy of 92.1%. Conclusion: Strain ratio elastography can be used as non-invasive tool to help in characterisation of benign and malignant breast lesions. Strain ratio elastography plays a significant role in complementing the conventional B mode ultrasonography for differentiation of benign and malignant lesions, thus preventing unnecessary intervention.