Ultrasonographic tissue quantification of the breast using acoustic radiation force impulse technology: phantom study and clinical application

Abstract

The aim of this study was to perform the phantom experiment and demonstrate the clinical usefulness of tissue quantification using a linear array transducer and acoustic radiation force impulse (ARFI) technology. For the phantom study, the commercially available Elasticity QA Phantom Model 049 was used. First, we measured the shear wave velocity (m/s) for the four spheres and the background of the phantom. Then, the shear wave velocity at nine sites was measured, with the region of interest being moved gradually from a shallow region (3 mm) to a deeper region (38 mm). For the clinical study, the shear wave velocities of 15 solid breast mass lesions were measured. The phantom study confirmed the feasibility of quantitative determination of the degree of tissue hardness. Dispersion of the measured values tended to be somewhat increased for the depths of 3 mm and 38 mm. The mean shear wave velocity was 2.07-2.93 m/s for five benign lesions, whereas higher shear wave velocities (n = 2) (7.15, 7.44 m/s) or "X.XX" (unmeasurable state) (n = 7) were found for malignant lesions other than mucinous carcinoma (2.44 m/s). ARFI tissue quantification is a potentially promising ultrasonographic technique for diagnosing breast lesions.