Elastography and Strain Ratio in Diagnosing Different Body Masses, Could They Solve the Puzzle?

Background: Different real time elasticity scores were developed to distinguish between benign and malignant lesions, yet the most important drawback is that they are very subjective. Strain ratio as a semi-quantitative method developed by dividing the area of interest by the normal tissue to improve objectivity and reach a better diagnosis. Aim: To validate the accuracy of elastography and strain ratio in diagnosing stiffness of different body masses. Patients and methods: This prospective study included 568 patients with different body masses and lymph nodes. We reached diagnosis in 427 patients by FNA, tru-cut and/or excision biopsy. Real time Elastography and strain ratio were assessed in all patient by US or EUS-elastography. Results: The best cut off value of strain ratio in differentiating benign from malignant lesions was 6.5 with 86% sensitivity, 84% specificity, 85% accuracy, 91% PPV and 76% NPV. Elastography score had sensitivity, specificity, accuracy, PPV and NPV of 94, 78, 88, 88, 87% respectively. Adding both results to each other resulted in sensitivity of 94%, specificity of 78%, accuracy, PPV and NPV of 88%. Conclusion: Using both strain ratio and elastography increases the accuracy of differentiating benign from malignant body lesions.