Synthetic Aperture Imaging in Breast Ultrasound: A Preliminary Clinical Study

Rationale and Objectives: To compare the image quality between conventional and synthetic aperture (SA) imaging in breast ultrasound (US). Materials and Methods: Twenty-four patients with 31 breast lesions were included in our study. The US data were processed with SA algorithm. For quantitative analysis, contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) were calculated. For qualitative analysis, conventional and SA images were reviewed by three radiologists and diagnostic preference (conspicuity, margin sharpness, and contrast) was assessed. The radiologists also determined whether artifacts were present. Parameters were analyzed using a paired t-test, Wilcoxon signed-rank test, and chi-square test. Results: The mean CNRs were higher in SA images compared with conventional images (mean, 2.56 versus 2.28, P=.004). The mean SNRs were higher in SA images compared with conventional images (31.62 versus 25.26, P <.0001). SA images were considered as being "better" or "much better" in 16-23 (51.6-74.2%) lesions of total 31 lesions for conspicuity, in 17-24 (45.2%-77.4%) for margin sharpness, and in 13-23 (41.9%-74.2%) for contrast. Significant preferences in SA images were demonstrated (conspicuity, P <.05 for all radiologists; margin sharpness and contrast in two radiologists). Refraction and speckle artifacts were less frequently observed in SA images (refraction, P <.05 for all radiologists; speckle, P <.05 for two radiologists), whereas reflection artifacts were more frequent in SA images (P <.05 in two radiologists). Conclusion: SA imaging provides better image quality than conventional imaging in patients with focal breast lesions in breast US.