Shea Butter as a Viable Couplant for Ultrasound Imaging

Abstract

Ultrasound imaging remains one of the widespread diagnostic imaging tools. The commercial coupling gel for ultrasound imaging is quite expensive and not readily available in developing countries. However, shea butter, which is abundant locally and affordable, has suitable acoustic properties that makes it worthwhile for consideration as a coupling agent. Thus, shea butter was investigated alternate coupling medium for ultrasound imaging. In the study, ultrasound images were acquired using commercially available gel and shea butter. The image quality assessment of the images obtained using the gel (reference sample) and shea butter (reference sample) were performed using mean pixel intensity, mean square error (MSE), peak signal to noise ratio (PSNR) and structural similarity index matrix (SSIM) as image quality metrics. The resulting computed values of the MSE, PSNR and SSIM were respectively 40.1283 ± 20.4941, 32.7450 ± 2.5722 and 0.5934 ± 0.1035 (mean ± standard deviation). The ranges of these metrics indicate that the images captured using gel and shea butter as couplants were comparable and supported the hypothesis that shea butter could be used as an ultrasound couplant. Using the Mann Whitney U test as a test of significance with α-value set at 0.05, there was no significant difference in the mean pixel intensities between the two set of images. This inference further buttressed the proposition that shea butter could be used as an alternate coupling medium for ultrasound imaging.