title: Smooth muscle cells of penis in the rat: noninvasive quantification with shear wave elastography.
abstract: OBJECTIVE
  Smooth muscle cells (SMCs) of cavernosum play an important role in erection. It is of great significance to quantitatively analyze the level of SMCs in penis. In this study, we investigated the feasibility of shear wave elastography (SWE) on evaluating the level of SMCs in penis quantitatively.
  
  
  METHODS
  Twenty healthy male rats were selected. The SWE imaging of penis was carried out and then immunohistochemistry analysis of penis was performed to analyze the expression of alpha smooth muscle actin in penis. The measurement index of SWE examination was tissue stiffness (TS). The measurement index of immunohistochemistry analysis was positive area percentage of alpha smooth muscle actin (AP).
  
  
  RESULTS
  Sixty sets of data of TS and AP were obtained. The results showed that TS was significantly correlated with AP and the correlation coefficient was -0.618 (p < 0.001). The result of TS had been plotted against the AP measurements. The relation between the two results has been fitted with quadric curve; the goodness-of-fit index was 0.364 (p < 0.001).
  
  
  CONCLUSIONS
  The level of SMCs in penis was successfully quantified in vivo with SWE. SWE can be used clinically for evaluating the level of SMCs in penis quantitatively.
authors.affiliation: Department of Medical Ultrasound, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China.
authors.forename: Jia-Jie
authors.initials: JJ
authors.lastname: Zhang
authors.affiliation: Department of Medical Ultrasound, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China.
authors.forename: Xiao-Hui
authors.initials: XH
authors.lastname: Qiao
authors.affiliation: Department of Medical Ultrasound, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
authors.affiliation: Department of Medical Ultrasound, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Bai
authors.affiliation: Department of Medical Ultrasound, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Li
authors.affiliation: Department of Medical Ultrasound, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China.
authors.forename: Lian-Fang
authors.initials: LF
authors.lastname: Du
authors.affiliation: Department of Medical Ultrasound, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China.
authors.forename: Jin-Fang
authors.initials: JF
authors.lastname: Xing
mesh_terms: D000818:Animals; D055119:Elastic Modulus / Q000502:physiology; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005240:Feasibility Studies; D008297:Male; D032389:Myocytes, Smooth Muscle / Q000000981:diagnostic imaging* / Q000502:physiology*; D010413:Penis / Q000166:cytology / Q000000981:diagnostic imaging* / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D033081:Shear Strength / Q000502:physiology; D013314:Stress, Mechanical; D013718:Tensile Strength / Q000502:physiology