Exploring shear-wave elastography and apparent diffusion coefficient in breast lesion characterization: diagnostic...

To compare shear-wave elastography (SWE) and diffusion-weighted imaging (DWI)-derived apparent diffusion coefficient (ADC) values in the differentiation of benign and malignant breast lesions, and to assess the correlation and potential interchangeability between these imaging biomarkers.

In this retrospective study, 53 female patients (mean age: 55.2 ± 11.7 years) with biopsy-proven BI-RADS 4 or 5 breast lesions underwent both SWE and breast MRI, including DWI. SWE parameters (Emax, Emean, Emin) and ADC values were quantitatively analyzed and compared using Mann-Whitney U tests. Diagnostic performance was evaluated via ROC analysis. Correlation and interchangeability between SWE and ADC were assessed using Spearman's rank correlation, regression analysis, and Bland-Altman plots.

Among 53 lesions (26 malignant, 27 benign), SWE Emax demonstrated the best diagnostic performance among SWE parameters (AUC = 0.74), with an optimal cut-off of > 69.47 kPa (sensitivity: 62%, specificity: 81%). ADC values achieved superior diagnostic accuracy (AUC = 0.94), with a cut-off of < 1182 × 10⁻⁶ mm²/s (sensitivity: 92%, specificity: 93%). A moderate inverse correlation was found between SWE Emax and ADC values (ρ = - 0.39, p = 0.004), but regression (R² = 0.19) and Bland-Altman analysis (limits of agreement ± 46%) indicated poor agreement and limited predictive utility.

These findings confirm that as tissue stiffness increases, water molecule diffusivity decreases. While SWE Emax and ADC values show a statistically significant inverse correlation, they are not interchangeable in clinical practice. ADC demonstrated superior performance as a standalone parameter for lesion characterization, whereas SWE retains value as a complementary tool within a multiparametric ultrasound approach. Further studies are warranted to confirm these findings in larger cohorts.