基于静动态磁共振成像比较正常青年男女盆底解剖结构及功能特征的差异

Comparative study of anatomical structure and functional characteristics of pelvic floor in normal young men and women by static and dynamic magnetic resonance imaging

目的利用静动态盆底磁共振成像技术比较正常青年男女盆底解剖结构及功能特征的差异。方法前瞻性收集健康青年志愿者男性60例,女性60例,使用3.0T MRI扫描仪行静态动态盆底MRI扫描。在静态及动态最大力排相矢状位T2WI图像上测量H线、M线、膀胱颈(bladder neck,BN)到耻骨尾骨线(pubococcygeal line,PCL)线的垂直距离(BN-PCL)、子宫(uterus)到PCL线的垂直距离(UPCL)、肛管直肠角、肛提肌板角、耻骨前列腺角,并计算上述参数静动态差值;在静态横轴位T2WI图像上测量耻骨直肠肌厚度和髂尾肌厚度。比较各参数两组间差异。结果正常青年男性静态M线长度、静态及动态最大力排相BN-PCL线长度明显大于女性(P<0.05);男性髂尾肌厚度明显大于女性(P<0.05);女性H线、BN-PCL线静动态差值明显大于男性(P<0.05)。结论静动态盆底MRI发现男性和女性肛直肠交界处、膀胱颈位置及盆底支持结构存在差异,提示临床医生利用磁共振技术评估盆底解剖结构及功能时应关注性别、个体差异,以提高盆底功能障碍性疾病的有效治愈率。

Objective To compare the differences of anatomical parameters of pelvic floor between normal young men and women by static and dynamic pelvic floor magnetic resonance imaging.Methods Sixty male and sixty female healthy young volunteers were prospectively collected.All volunteers underwent static and dynamic pelvic floor MRI with 3.0T MRI scanners.The length of H line,the length of M line,the vertical distance from bladder neck(BN)to pubococcygeal line(PCL line)(BN-PCL),the vertical distance from uterus to PCL line(U-PCL),anorectal angle(ARA),levator ani plate angle(LPA),puboprostatic angle(PPA)were measured on static and dynamic maximum force phase sagittal T2WI images,and the static and dynamic differences of the above parameters were calculated.The thickness of puborectal muscle(PRM)and iliococcygeal muscle(ICM)were measured on static axial T2WI images.The differences of the parameters between the two groups were compared whether there was statistical significance or not.Results The static M line length,static and dynamic maximum force phase BN-PCL line length of normal young male were significantly longer than that of female(P<0.05);the thickness of iliococcygeal muscle in male was significantly higher than that in female(P<0.05);by comparing the changes of parameters in the two states,the length changes of H line and BN-PCL line in female were significantly greater than those in male(P<0.05).Conclusions Static and dynamic MRI shows that there are difference in anorectal junction,bladder neck position and pelvic floor supporting structure between men and women,suggesting that clinicians should pay attention to gender and individual differences when evaluating the anatomical structure and function of pelvic floor by magnetic resonance imaging,so as to improve the effective cure rate of pelvic floor dysfunctional diseases(PFD).