Diagnostic value of diffusion-weighted imaging combined with DCE-MRI time-signal intensity curve for differentiating benign from malignant BI-RADS 4 breast lesions.

Objective

To determine whether intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) parameters combined with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) time-signal intensity curve (TIC) can help distinguish benign from malignant BI-RADS 4 breast lesions.

Materials And Methods

This retrospective study included 81 women with pathologically confirmed BI-RADS 4 breast lesions (22 benign, 59 malignant). For each lesion, TIC type, apparent diffusion coefficient (ADC), pure diffusion coefficient (D), pseudodiffusion coefficient (D*), and perfusion fraction (f) were recorded. Pathological results served as the reference standard. Each parameter was compared between benign and malignant groups using independent t‑test or Mann‑Whitney U test. Diagnostic models were built using binary logistic regression, and their performance was assessed with ROC curves and leave‑one‑out cross‑validation.

Results

Malignant lesions had significantly lower ADC and D values than benign ones (both P < 0.05). D* and f did not differ between groups. Type III TIC was much more common in malignant than in benign lesions (P < 0.05). Among individual parameters, ADC performed best (AUC = 0.83, 95 % CI: 0.72-0.94). Adding TIC to ADC raised the AUC to 0.88, with sensitivity 0.93, specificity 0.73 and accuracy 0.88.

Conclusion

Both DWI parameters (especially ADC and D) and TIC type help differentiate benign from malignant BI-RADS 4 lesions. The ADC combined with TIC model offers better diagnostic accuracy and is practical for clinical use.