School of Rehabilitation, Faculty of Medicine and Health Sciences, Université de Sherbrooke and Research Center of the Centre Hospitalier de l'Université de Sherbrooke (CHUS), Sherbrooke, Québec, Canada.
School of Health and Rehabilitation Sciences, Center for Clinical Research Excellence in Spinal Pain, Injury and Health, The University of Queensland, Brisbane, Queensland, Australia.
Neurourol Urodyn. 2022 Sep;41(7):1620-1628. doi: 10.1002/nau.25010. Epub 2022 Jul 17.
To investigate the validity of shear wave elastography (SWE) as a measure of stiffness of the puborectalis muscle by examining: (1) the relationship between puborectalis muscle stiffness and pelvic floor muscle (PFM) activation at different intensities; and (2) the relationship between puborectalis stiffness and pelvic floor morphometry during contractions at different intensities.
Fifteen healthy asymptomatic women performed 6-s isometric PFM contractions at different intensities (0, 10%, 20%, 30%, 50%, 75%, and 100% of maximal voluntary contraction) guided by intravaginal electromyography (EMG). Stiffness of the puborectalis muscle was measured using SWE by calculating the average shear modulus in regions of interest that contained puborectalis muscle fibers parallel to the transducer. Pelvic floor morphometry was assessed in the mid-sagittal plane using transperineal B-mode ultrasound imaging. Shear modulus, EMG (root mean square amplitude) and pelvic floor morphometry parameters were normalized to the value recorded during maximal voluntary contraction. To assess the relationship between stiffness and pelvic floor activation/morphometry, coefficient of determination (r ) was calculated for each participant and a group average was computed.
Shear modulus and EMG were highly correlated (average r ; left 0.90 ± 0.08, right 0.87 ± 0.15). Shear modulus also strongly correlated with bladder neck position (x-axis horizontal coordinates relative to the pubic symphysis), anorectal rectal angle and position, levator plate angle, and antero-posterior diameter of the levator hiatus (average r : range 0.62-0.78).
These findings support the validity of SWE to assess puborectalis muscle stiffness in females. Stiffness measures were strongly associated with PFM EMG and pelvic floor morphometry and may be used to indirectly assess the level of activation of the puborectalis muscle without the use of more invasive techniques. By overcoming limitations of current assessment tools, this promising noninvasive and real-time technique could enable important breakthrough in the pathophysiology and management of pelvic floor disorders.
通过研究：（1）肛提肌硬度与不同强度盆底肌（PFM）激活之间的关系；（2）不同强度收缩时肛提肌硬度与盆底形态之间的关系，来探讨剪切波弹性成像（SWE）作为肛提肌硬度测量方法的有效性。
15 名健康无症状女性在阴道内肌电图（EMG）引导下，进行 6 秒等长 PFM 收缩，强度分别为 0、10%、20%、30%、50%、75%和 100%最大随意收缩。使用 SWE 测量肛提肌硬度，通过计算包含与换能器平行的肛提肌纤维的感兴趣区的平均剪切模量来实现。在会阴旁矢状面使用经会阴 B 型超声成像评估盆底形态。将剪切模量、EMG（均方根振幅）和盆底形态参数归一化为最大随意收缩时记录的值。为了评估硬度与盆底激活/形态之间的关系，为每个参与者计算决定系数（r），并计算组平均值。
剪切模量与 EMG 高度相关（左侧平均 r：0.90±0.08，右侧平均 r：0.87±0.15）。剪切模量也与膀胱颈位置（耻骨联合前 x 轴水平坐标）、肛直肠角和位置、肛提肌板角和肛提肌裂孔前后径强烈相关（平均 r：范围 0.62-0.78）。
这些发现支持 SWE 用于评估女性肛提肌硬度的有效性。硬度测量与 PFM EMG 和盆底形态密切相关，可用于在不使用更具侵入性技术的情况下间接评估肛提肌的激活程度。通过克服当前评估工具的局限性，这种有前途的非侵入性和实时技术可能会在盆底功能障碍的病理生理学和管理方面带来重要突破。
