Objective: To determine the value of combining conventional ultrasonography with virtual touch tissue imaging quantification (VTIQ) for differential diagnosis of breast lesions smaller than 10 mm.
Methods: A total of 98 breast lesions smaller than 10 mm were examined by conventional ultrasound and VTIQ using a Siemens ACUSON S3000 ultrasound machine. Pathologic diagnosis was established after surgery or fine needle biopsy.
Results: Malignant lesions were characterized by taller-than-wide shape, poorly circumscribed margin, and marked hypoechogenicity. The mean VTIQ shear wave velocity (SWV) value of malignant lesions was 4.88±1.87 m/s (range, 1.75-9.34 m/s), significantly higher than that of benign lesions (2.68±1.02 m/s; range, 1.18-4.67 m/s). The optimal cutoff SWV value was 3.27 m/s, with sensitivity, specificity, diagnostic accuracy, positive predictive value (PPV), and negative predictive value (NPV) of 86.20%, 95.65%, 92.86%, 89.29%, and 94.29%, respectively. The combination of SWV >3.27 m/s plus the US feature of poorly circumscribed margin had the highest sensitivity (93.33%) and specificity (100%) for diagnosis of malignant breast lesions.
Conclusion: Features such as taller-than-wide shape, poorly circumscribed margin, and marked hypoechogenicity on conventional US, and SWV >3.27 m/s on VTIQ, are indicators of malignancy in breast lesions with diameter <10 mm. The combination of poorly circumscribed margin and SWV >3.27 m/s provides the highest specificity and diagnostic accuracy.
Keywords: Conventional ultrasonography; breast lesions; virtual touch tissue imaging quantification.