摘要目的：探讨女性压力性尿失禁（SUI）患者尿道括约肌的MRI特征。方法回顾性分析经临床确诊的女性SUI患者40例作为SUI组，招募无症状成年女性志愿者40名作为对照组。所有受检者均分别在静息态、Valsalva状态（屏气做最大用力排尿动作）行盆腔MRI平扫。静息态下测量尿道中段外括约肌厚度；在静息和Valsalva状态下测量功能尿道长度，并观察膀胱颈漏斗的有无。SUI组和对照组尿道中段外括约肌厚度、功能尿道长度的比较采用两独立样本t检验，膀胱颈漏斗阳性率的比较采用χ2检验；各组受试者静息态及Valsalva状态下功能尿道长度的比较采用配对t检验。结果SUI组、对照组静息态尿道中段外括约肌厚度分别为（2.23±0.68）、（2.69±0.75）mm，差异有统计学意义（t=－2.839，P<0.01）。静息态下，SUI组、对照组的功能尿道长度分别为（2.72±0.51）、（2.94±0.34）cm；Valsalva状态下，2组的功能尿道长度分别为（2.33±0.49）、（2.43±0.43）cm。SUI组和对照组受试者在静息态下功能尿道长度均大于Valsalva状态下功能尿道长度，差异均有统计学意义（P均<0.01），SUI组和对照组相比，静息态下功能尿道长度差异有统计学意义（t=－2.322，P=0.023），Valsalva状态下功能尿道长度差异无统计学意义（t=－1.049，P=0.297）。静息态SUI组膀胱颈漏斗阳性29例，对照组9名，差异有统计学意义（χ2=20.050，P<0.01）。结论女性SUI患者尿道中段外括约肌厚度变薄，功能尿道长度缩短，且膀胱颈漏斗出现的阳性率较高。

abstractsObjective To investigate the MRI features of urethral sphincter in female with stress urinary incontinence(SUI) by the study of the indexes of the thickness of middle urethral sphincter, the function urethral length and bladder neck funnel . Methods Forty patients of female patients diagnosed as SUI by clinical were retrospectively as SUI group, and 40 asymptomatic female volunteers were recruited as reference group. All of the subjects were tested by pelvic MRI scanning both in static status and in the condition of Valsalva. The thickness of middle urinary sphincter was measured in the horizontal axis plane. In the midsagittal plane, the function urethral length was measured from the internal orifice to perineal fascia. The bladder neck funnel whether exist was observed from the midsagittal plane. For the comparison of the urinary sphincter thickness and urethral length of the two groups, independent sample t test was adopted. For urethral length in static status and under the condition of Valsalva, paired t test was done. For comparison of positive rate of the bladder neck funnel, Chi?squared test has been done. Results The value of the middle urinary sphincter thickness in the groups of SUI and reference were (2.23±0.68) mm and (2.69± 0.75) mm, respectively. Thus the differences of the two groups had statistical significance (t=-2.839, P<0.01 ). In the static status, the urethral length in SUI and reference group were (2.72±0.51) cm and (2.94± 0.34) cm respectively, wheras in Valsalva condition, the value were (2.33 ± 0.49) cm and (2.43 ± 0.43) cm respectively. The differences of the two groups had statistical significance in static status (t=-2.322, P=0.023), wheras there had no statistical significance in the two groups in Valsalva condition (t=-1.049,P=0.297). For SUI and reference group, both in static status and Valsalva condition, the difference of function&nbsp;urethral length had statistical significance (P< 0.01). The positive rate of bladder neck funnel for SUI was 72.5% (29/40), and for reference was 22.5% (9/40), the difference of the two groups had statistical significance(χ2=20.050, P<0.01). Conclusion For female SUI patients, urinary sphincter muscle is much thinner, function urethral length is much shorter and has higher positive rate of bladder neck funnel.