Does the addition of contrast-enhanced ultrasonography to B-mode ultrasonography improve diagnostic accuracy for breast cancer? A systematic review and meta-analysis.

PURPOSE: This study aimed to determine whether the addition of contrast-enhanced ultrasonography (CEUS) to B-mode ultrasonography improves diagnostic accuracy in differentiating benign from malignant breast lesions. METHODS: A comprehensive literature search was performed using PubMed (MEDLINE), Ichushi, and the Cochrane Library up to July 2025. Eligible studies assessed the diagnostic performance of CEUS for suspected breast cancer, with histopathology as the reference standard. Pooled sensitivity, specificity, diagnostic odds ratio (DOR), and positive and negative likelihood ratios were calculated. RESULTS: Eleven studies comprising 1987 patients with 2051 lesions were included. The pooled sensitivity and specificity of B-mode ultrasonography alone were 86.1% (95% confidence interval [CI] 81.5-89.7) and 70.8% (95%CI 60.7-79.2), respectively. For B-mode alone, the pooled DOR was 15.0 (95%CI 9.7-23.3), with an LR + of 2.95 (95% CI 2.18-3.99) and an LR - of 0.20 (95% CI 0.15-0.26). In contrast, CEUS was associated with improved pooled estimates of diagnostic performance, yielding a pooled sensitivity of 93.4% (95%CI 89.0-96.2) and a specificity of 85.8% (95%CI 80.9-89.6). The pooled DOR for CEUS was 86.3 (95%CI 48.0-155.4), with an LR + of 6.59 (95%CI 4.89-8.87) and an LR - of 0.08 (95%CI 0.05-0.13). CONCLUSIONS: Pooled diagnostic estimates were higher in studies evaluating CEUS combined with B-mode ultrasonography than in studies evaluating B-mode ultrasonography alone, particularly by increasing specificity in differentiating benign from malignant breast lesions. However, these findings are based on indirect comparisons and should be interpreted with caution.