Factors affecting the shear wave elastic quantitative measurement of penile tissue in rats.

Background: As a new ultrasound technology, 2-dimensional shear wave elastography (2D-SWE) can evaluate the elastic characteristics of penile tissue. However, no studies have reported the main factors affecting the shear wave elastic quantitative measurement (SWQ) in penile tissue.
Objectives: To analyze the main factors affecting the SWQ reflecting the elastic characteristics of penile tissue by 2D-SWE.
Methods: Twenty healthy male Sprague-Dawley rats (5-60 weeks old) were selected for this study. We performed the 2D-SWE examination on the penis using the Aixplorer ultrasound system, with SWQ as the measurement index. We performed penile immunohistochemistry analysis with the positive area proportion (PAP) of alpha-smooth muscle actin (PAP _S ) and type III collagen fiber (PAP _C ) as the outcomes. Then, we conducted multiple linear regression analysis to explore the correlation of SWQ with PAP _S and PAP _C and established the regression equation.
Results: The multiple linear regression analysis showed that the linear regression equation (SWQ = 10.376 - 0.05 PAP _S - 0.07 PAP _C ) was statistically significant ( F = 21.153, P < 0.001). The content of smooth muscle cells (SMCs) and collagen fibers was negatively correlated with SWQ, affecting 42.6% of the total variation in SWQ ( R ² = 0.426).
Conclusions: SMCs and collagen fibers are the main factors affecting the SWQ value of penile tissue and the primary tissue components determining the SWQ when using 2D-SWE to quantitatively evaluate the elastic characteristics of penile tissue.
(© 2023 Wan-Ting Rao et al., published by Sciendo.)