Experimental investigation of early assessment of corpora cavernosa fibrosis with two-dimensional shear wave elastography

Abstract

This study explored the usefulness of two-dimensional shear wave elastography (2D-SWE) in the early assessment of corpora cavernosa fibrosis (CCF). New Zealand male rabbits were randomly assigned to an experimental group or a control group. Recombinant human transforming growth factor beta 1 (TGF-β1) was injected into the dorsal penis tissue of rabbits in the experimental group. Conventional ultrasound and 2D-SWE examinations were performed before and 20 days after injection. Penile histological analysis was performed by hematoxylin–eosin staining, sirius red staining, and immunohistochemistry. Measurement of 2D-SWE examination results was performed using shear wave elastography quantitative measurement (SWQ). Histological analysis outcomes were the proportion of smooth muscle cells (SMCs), collagen fibers (CFs), collagen type I (Col I), and collagen type III (Col III), as well as the SMCs/CFs ratio, measured by sirius red staining. Other histological analysis outcomes were the positive area proportion (PAP) of TGF-β1 (PAPT), fibronectin (PAPF), and Col III (PAPC), measured by immunohistochemistry. After recombinant human TGF-β1 injection, SWQ was higher in the experimental group than that in the control group (P < 0.001); however, there were no differences in conventional ultrasound results. There were significant differences in histological outcomes between the two groups (all P < 0.05). These results indicated that 2D-SWE was superior for identifying early histological changes in CCF.

Keywords

• collagen type i; collagen type iii; elastography; penis; smooth muscle cells