A preliminary prospective study to compare the diagnostic performance of assist strain ratio versus manual strain ratio

The objectives of this study were to demonstrate the non-inferiority of assist strain ratio (ASR)-a newly developed application tool-to manual strain ratio (MSR)-a currently available standard diagnostic tool-and to calculate the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of MSR and ASR.

Ninety-eight mass lesions in the mammary gland (30 malignant and 68 benign) were included in the study. Skilled physicians performed the elastography scanning by applying minimal vibration. MSRs were obtained and compared with ASRs calculated from the same elastography image to test the correlation between the two groups of data.

Diagnostic performance of MSR at a cut-off of 5.0 showed a sensitivity of 84.4 %, a specificity of 80.4 %, an accuracy of 81.6 %, a PPV of 65.5 %, and an NPV of 92.1 %. Diagnostic performance of ASR at a cut-off of 5.0 showed a sensitivity of 74.4 %, a specificity of 84.3 %, an accuracy of 81.3 %, a PPV of 67.7 %, and an NPV of 88.2 %. The areas under the curve (AUCs) for MSR and ASR were found to be 0.885 and 0.875, respectively.

ASR demonstrated excellent diagnostic potential and was highly correlated with MSR performed by skilled physicians (r = 0.69, p < 0.05).