To assess the value of virtual touch tissue imaging quantification (VTIQ) shear wave elastography combined with pelvic ultrasound in the diagnosis of pelvic floor dysfunction (PFD) after vaginal delivery.

From January 2019 to December 2019, 42 patients with PFD treated at Hainan Affiliated Hospital of Hainan Medical University Hospital after vaginal delivery were selected as a PFD group, and 52 healthy volunteers without PFD were included in a control group. All patients underwent pelvic ultrasound and VTIQ shear wave elastography. The clinical data of the two groups were recorded and compared, including age, body mass index, parity, the mean of birth weight, pelvic floor ultrasound parameters [bladder neck descent (BND), posterior urethrovesical angle (PUVA), urethral rotation angle (URA), cervical orifice descent (COD), rectal ampulla descent (RAD), and levator hiatus area (LHA)], and elastic ultrasound parameters [Young's modulus of the puborectalis (PR) at resting and maximum anal contraction state]. Rank sum test and t-test were used to screen out indicators with diagnostic value for PFD, and a binary logistic regression model was developed to identify the independent factors for postpartum PFD. Receiver-operating characteristic curve (ROC) analysis was performed to analyze the diagnostic value of single parameter and regression model, and the area under curve (AUC) was compared.

There were significant differences in parity, the mean of birth weight, BND, PUVA, URA, COD, RAD, LHA, Young's modulus of PR at maximum anal contraction state, and Young's modulus difference between the two groups (P＜0.05). The AUC of Young's modulus difference was higher than that of Young's modulus at maximum anal contraction state between the two groups (0.865 vs 0.750; Z=2.844, P＜0.001). Binary logistic regression analysis showed that the mean of birth weight (X₄), BND (X₅), and LHA (X₁₀) were identified as independent risk factors, and Young's modulus difference (X₁₃) was identified as an independent protective factor for PFD after vaginal delivery. The developed logistic regression equation was: Logit (P) =-60.011+0.010X₄+0.599X₅+1.202X₁₀-0.416X₁₃. ROC curves analysis indicated that the AUCs of the mean of birth weight, BND, LHA, Young's modulus difference, and the regression model for predicting PFD after vaginal delivery were 0.779, 0.836, 0.876, 0.865, and 0.996, respectively. The AUC of the regression model was significantly higher than those of other indexes (P＜0.001,＜0.001, =0.006, and =0.013, respectively), but the AUCs of the other indexes did not differ significantly (P＞0.05). When the prediction probability of the regression model was 0.5454, the sensitivity and specificity were 88.10% and 94.23%, respectively.

The regression model established by VTIQ technology combined with pelvic ultrasound has high diagnostic value for PFD after vaginal delivery.