Evaluation Of Biomechanical Properties Of Female Pelvic Floor Muscles With Ultrasonic Shear Wave Elastography

Female pelvic floor dysfunction is a common chronic disease in middle-aged and elderly women with pelvic organ shifting and dysfunction caused by the progressive decline of biomechanical properties of pelvic floor support tissues.The cardinal symptoms are: pelvic organ prolapse(POP),stress urinary incontinence(SUI),fecal incontinence(FI)and sexual dysfunction(SD),seriously threaten women’s physical and mental health,affect their normal social activities,and reduce women’s quality of life.The pelvic floor muscle is the core of the pelvic floor support tissue.Therefore,the analysis of the biomechanical properties of the pelvic floor muscle can help us understand the functional damage or degradation mechanism of the pelvic floor support tissue.However,the pelvic floor muscle evaluation methods,like traditional mechanical test,electromyography,general medical imaging techniques,urodynamics,and existing elastography assessments are not capable of both quantitative and real-time visualization in-vivo,directly reflect the intrinsic biomechanical properties of the pelvic floor muscles.Therefore,there is urgent to develop a new technology that contains the above characteristics to promote the progress in diagnosis and treatment of pelvic floor dysfunction diseases.The shear elastic modulus is one of the most widely existed physical parameters in biological soft tissue,and it is highly sensitive to physiological and pathological changes accompanied by biological soft tissue structure,which can be used as an important index for clinical diagnosis.To this end,using ultrasound shear wave elastography based on Verasonics Vantage 256 to analyze POP patients’ pelvic floor muscle shear wave velocity under different contraction strengths,to evaluate the shear elastic modulus of pelvic floor muscle and explore the application value of our platform in the clinical diagnosis and treatment of pelvic floor dysfunction.The main contents of this study include:(1)selecting algorithm by standard heterogeneous phantom experiment and Field II sound simulation—focus comb pulse shear wave elastography;(2)through dynamic mechanical and ultrasonic shear wave data analysis on homogeneous polyvinyl alcohol phantom to determine the setting of algorithm parameters;(3)custom-making static tensile-test set-up,preparation of anisotropic polyvinyl alcohol phantom and isolated pork phantom,quantitatively characterize the ratio of anisotropy,verified that the algorithm can be used to evaluate the anisotropic mechanical properties of tissue;(4)cooperating with the ultrasonic diagnosis pelvic floor specialist of the Second People’s Hospital of Shenzhen,the statistical analysis of 11 cases of pelvic organ prolapse in the levator ani muscle showed a significant difference in shear elasticity(P?0.001),indicating that the ultrasonic data acquisition platform built in this study can be used for the evaluation of pelvic organ prolapse,and has the value of quantitative evaluation for clinical pelvic floor dysfunction.