Evaluation Of Changes Of Perineal Body Muscle Tension By Swe Imaging Combined Gray-scale Ultrasound

Objectives:To evaluate the influence of different delivery way for the perineal body(PB)tension of primipara by using shear wave elastography(SWE)combined gray-scale ultrasound to study different labor primipara,s modulus and size of PB.Methods:1.205 cases of primipara treated at 42 to56 days after dellvery in the Department of Gynecology and Obstetrics of the First Affiliated Hospital of Nanchang University from December 2016 to January 2018 were selected as fertile group,and then they were divided into elective cesarean delivery group(n =70),transit cesarean delivery group(n =55),and vaginal delivery group(n =80),all were primipara G1P1.80 cases of normal medical examination nulliparous women as control group during the same period.The age,height and weight of all the subjects were recorded.2.The depth,height and Young's modulus of perineal body were measured by using gray-scale sonography and SWE during resting and retraction status.Each ultrasound parameter value was calculated to evaluate the effects of different delivery modes on the morphology and muscle stiffness of the perineal body.Results:1.According to the research object selection criteria,a total of 285 subjects were included in the study.In this study,285 subjects were able to obtain satisfactory conventional two-dimensional gray-scale images and stable SWE elastic images.2.The results of conventional two-dimensional gray-scale ultrasound morphological parameters showed that The perineal body depth,height contraction amplitude difference had statistical significance between the four groups of study objects(P< 0.05),and the contraction amplitude of the perineal body in the fertile group was lower than that in the nulliparous group.The amplitude of perineal contraction in elective cesarean delivery group was higher than that in transitional cesarean delivery group and vaginal vaginal delivery group,the difference of ultrasound parameters between these groups was statistically significant(P< 0.05).3.The Young's modulus during resting and contraction differed significantly between the four groups(P< 0.05).Resting state: The mean Young's modulus in the nulliparous group was 34.90±3.86 kPa,which was higher than those in the elective cesarean delivery group(30.75±4.52 kPa),transit cesarean section(30.75±4.52 kPa)and vaginal delivery group(26.93±1.53kPa)(P < 0.05).Contraction state: The mean Young's modulus in the nulliparous group was 45.57±3.56 kPa,which was higher than that of the elective cesarean section(39.24±4.30 kPa)and the transit cesarean section(33.36 ± 1.70 kPa),and vaginal delivery group(28.15 ± 4.24 kPa),the differences were statistically significant(P both <0.05).Conclusion:1.The conventional two-dimensional gray-scale ultrasound suggested that the contraction amplitude of the perineal body in the initial parturition was weakened,and the reduction degree of the contraction amplitude of the perineal body in the different delivery groups was significantly different.2.The SWE ultrasound elastography showed that the average Young's modulus value of the perineal body of the fertile group were reduced,and the Young's modulus value of the fertile group with different delivery methods had significant differences.3.The ultrasound imaging is expected to become a new and non-invasive method for clinicians to assess the degree of the perineal body injury in the pregnancy and delivery process and its future recovery.