Abstract：Objective: To observe the pelvic diaphragm hiatus in nulliparous women with three-dimensional ultrasound, in order to assess the value of three-dimensional ultrasound in observing the female pelvic diaphragm. Methods: Forty-five nulliparous women were enrolled in the study, ultrasonogram of pelvic diaphragm hiatus was acquired by using three-dimensional ultrasound. The form, structures of hiatus were observed, the anteroposterior diameter, transverse diameter, area and circumference of pelvic diaphragm hiatus and the thickness of puborectalis were measured at rest and during maximum Valsalva maneuver. Result: Through the pelvic diaphragm hiatus, the urethra, vagina and rectum arranged in rhombic shape from front to back, and puborectalis at both sides of the pelvic diaphragm hiatus were symmetrical and continuous. The morphology and internal anatomical structures of levator hiatus showed no notable alternations at rest and during maximum Valsalva maneuver, the sizes of levator hiatus and the thickness of puborectalis changed significantly. The anteroposterior diameter, transverse diameter, area and circumference of pelvic diaphragm hiatus were (3.53±0.42) cm, (4.62±0.46) cm, (12.08±1.43) cm2 and (13.39±1.62) cm at rest. During maximum Valsalva maneuver, the sizes were(4.03±0.39) cm, (5.08±0.62) cm, (14.29±1.92) cm2 and (14.54±1.68) cm. The thickness of left puborectalis was (0.71±0.10) cm at rest and (0.60±0.08) cm during maximum Valsalva maneuver, and that of the right was (0.68±0.08) cm at rest and (0.58±0.07) cm during maximum Valsalva maneuver. The size of levator hiatus was larger and the thickness of puborectalis was thinner during maximum Valsalva maneuver compared with the condition at rest. There were significant differences(P<0.05). Conclusion: The three-dimensional ultrasound technology is an effective imaging method to estimate the female pelvic diaphragm.
2015, Vol. 26 
