Combined speed of sound correction and coherence masking improves ultrasound imaging of renal cysts

Renal cystic lesions are common, with approximately 25% of individuals over 40 and 50% over 50 having at least one cyst, the majority of which are benign. However, some lesions can become malignant, necessitating regular imaging to distinguish between benign and malignant cysts. Ultrasound (US) is a preferred imaging modality due to its safety and cost-effectiveness, but its efficacy is often limited in obese patients due to poor image quality resulting from fat attenuation and phase aberration. This can lead to misdiagnoses, as smaller features indicative of pathology can be obscured or made ambiguous. In this study, we employ a two-stage approach to enhance in vivo US images of renal cysts. First, a bulk speed of sound correction is applied to optimize resolution in the delay-and-sum images. Next, we implement a spatial correction based on short-lag spatial coherence of the channel data, computed for the identified optimal speed of sound. Among all subjects (N = 10) with body mass indices ranging from 18 to 38, cystic boundaries were sharpened, and the generalized contrast-to-noise ratio (gCNR) improved by 7.4% [CI (5.5, 9.2)%, p < 0.0001] compared to uncorrected delay-and-sum images. Furthermore, the weighting of the coherence mask can be varied in real time during evaluation to enhance the diagnostic value of the composite image. This approach demonstrates significant potential for rapid clinical translation and for augmenting the critical role of US in monitoring kidney cysts.