Assessment of choroidal melanoma and nevus lesions using ultrasound vibro-elastography and parametric imaging...

The purpose of this study was to assess eye lesions by analyzing wave speed (WS) of lesions using ultrasound vibro-elastography (UVE) together with a parametric ultrasound imaging approach. Ten subjects with eye lesions (5 nevus (N) vs. 5 melanoma (M)) were recruited and tested using UVE. In addition, the sliding window method was used to reconstruct and analyze horizontal Normalized Shannon Entropy (hNSE) images and Nakagami-m/omega images. Two-way ANOVA statistical analysis was performed to compare mean values of the contrast to noise ratio (CNR), hNSE, and m/omega of these images between the two types of lesions. The results show that there were significant differences in CNR of the m map images (p = 0.0174) and omega map images (p = 0.0128) reconstructed from shear wave velocity (SWV) between the two types of lesions and significant differences in CNR of the m map images (p = 0.0209) and omega map images (p < 0.0001) reconstructed from two dimensional (2D) speed maps between the two lesions Furthermore, the m values of 2D speed maps shows significant differences between N vs. M of all three frequencies (i.e., 100 Hz (p = 0.0052), 150 Hz (p = 0.0100), 200 Hz (p = 0.0174)). The results suggest that CNR, m and omega of Nakagami method are useful biomarkers for assessing eye lesion with UVE technique. Nakagami imaging of SWV and 2D speed maps have better performance than hNSE imaging for analyzing characteristics of eye lesions. UVE based Nakagami imaging is a promising method for evaluating eye lesions.