Differential diagnostic performance of acoustic radiation force impulse imaging in small (≤ 20 mm) breast cancers: Is it valuable?

To evaluate acoustic radiation force impulse (ARFI) inthe differential diagnosis of small (<= 20 mm) solid breast lesions and identify the most efficient ARFI parameters. Conventional ultrasonography and ARFIwere performed in 120 patients with 121 small solid breast lesions. The area ratios (ARs) of the lesion on virtual touch tissue compared to B-mode were calculated. The shear wave velocity of the inner (SWVi) and boundary (SWVb) of the lesions and surrounding fatty tissue (SWVf) was measured. The ratio of SWVi to SWVf (SWVrat) was calculated. AR, SWVi, SWVb, and SWVrat were significantly larger in malignant lesions (all P < 0.001). A cutoff AR of 1.17 yielded the highest area under the receiver operating characteristic curveamong the various parameters (91.2% sensitivity, 85.9% specificity, 88.4% accuracy) for the differential diagnosis of small breast lesions, but this value did not significantly differ from SWVi (P = 0.1144). This AR cutoff indowngradingcategory 4a to category 3 would avoid 83.3% unnecessary biopsies, and improved diagnostic specificity up to 73.4% without decreasing sensitivity. AR and SWVi are efficient parameters for the differential diagnosis of small breast lesions, whichwill improve diagnostic specificity and reduce unnecessary biopsies.