扩散张量成像对盆腔器官脱垂患者盆底肌肉的评估

Evaluating Pelvic Floor Muscles in Patients with Pelvic Organ Prolapse Using Diffusion Tensor Imaging

目的采用扩散张量成像(DTI)评价女性盆腔器官脱垂(POP)患者盆底肌肉的参数变化。资料与方法收集50例POP III度以上的患者作为研究组,50例健康女性志愿者作为对照组,进行横轴位DTI扫描,b=500 s/mm2,15个方向。将DTI原始图像导入后处理软件,分别形成相应的参数图,在b=0的原始图像上逐层勾画盆底各肌肉的边缘并计算出各DTI参数,测量会阴浅横肌、耻骨内脏肌、耻骨直肠肌、髂骨尾骨肌和闭孔内肌5种盆底双侧肌肉和肛门括约肌的DTI参数,包括各向异性分数(FA)、平均扩散度(MD)、λ1、λ2、λ3、线性各向异性(CL)、平面各向异性(CP)和球面各向异性(CS)。比较每种肌肉左右侧、研究组与对照组间DTI参数值的差异。结果对照组的5种盆底双侧肌肉中,仅闭孔内肌左、右侧肌肉的FA、λ3、CP、CS值差异有统计学意义(P<0.01、P<0.001);研究组仅闭孔内肌左、右侧肌肉的FA、λ3、CL、CP、CS值差异有统计学意义(P<0.05、P<0.001)。研究组和对照组相比,会阴浅横肌FA值和CS值,左侧耻骨内脏肌CL值,右侧耻骨内脏肌FA、λ3、CL、CS、CP值和左侧髂尾肌λ1、λ3值差异有统计学意义(P<0.01、P<0.05)。结论 DTI观察女性盆底肌肉技术上可行,可对POP患者的盆底肌肉损伤进行初步评估,并对揭示其发病机制有一定的作用。

Purpose To evaluate parameter changes of pelvic floor muscles in patients with female pelvic organ prolapse （POP） through diffusion tensor imaging （DTI）. Materials and Methods Fifty female patients with POP at III or IV degree （research group） and fifty healthy women volunteers （control group） were collected to make prospective research. The axial DTI sequence was performed in subjects, with b=500 s/mm2, at 15 directions. DTI original images were imported into the post-processing software, and the corresponding DTI mappings were formed. In the original images, pelvic floor muscles were sketched out layer by layer, and various DTI parameters, including fractional anisotrophy （FA）, mean diffusivity （MD）, λ1, λ2, λ3, linear anisotropy （CL）, planar anisotropy （CP） and spherical anisotropy （CS）, were calculated. Six kinds of pelvic floor muscles, including anal sphincter, superficial transverse perineal muscle, pubic visceral muscle, puborectal muscle and iliococcygeal muscle were measured, and five of them were measured on both sides. The difference of DTI parameters between right and left side of each muscle, and the difference of DTI parameters between research and control group were compared. Results Between the right and left side of five kinds of pelvic floor muscles in control group, significant difference was only found in FA, λ3, CP, CS value of internal obturator muscle （P〈0.01, P〈0.001）. There were significant differences in FA, λ3, CL, CP and CS values of the left and right muscles in the study group （P〈0.05, P〈0.001）. Compared with control group, FA value and CS value of superficial transverse perineal muscle, CL value of left pubic visceral muscle, FA, λ3, CL, CS and CP value of right pubic visceral muscle, λ1 and λ3 value of left iliococcygeal muscle of research group were significantly different （P〈0.01, P〈0.05）. Conclusion DTI for observation of female pelvic floor muscle is technically feasible, and it can detect the injury of pelvic floor muscle in POP patients, and may be helpful to reveal the pathogenesis of POP.