To assess the diagnostic value of contrast-enhanced ultrasound (CEUS) in uterine scar after cesarean section by comparing with transvaginal ultrasound (TVS).

From May 2017 to May 2019, 75 patients at Beijing Shijitan Hospital with a history of previous cesarean section for more than 6 months were included. All the patients underwent TVS and CEUS, and 11 patients underwent saline infusion sonohysterography. The detection rate and diagnosis accuracy of CEUS were assessed by comparing with TVS and saline infusion sonohysterography. The results of CEUS and TVS in measuring the morphological parameters of cesarean scar diverticulum (CSD) were compared. The relationship between TIC parameters and CSD was analyzed.

The detection rate of CSD by TVS was 53.3% (40/75) versus 68% (51/75) by CEUS, and there was a statistical difference between them (χ²=40.336, P<0.05). Compared with TVS, the CSD measured by CEUS was deeper, and the residual myometrium was thinner; there was a statistical difference between them (t=4.463 and 6.480, respectively; P<0.001). CSD showed higher peak intensity and greater enhancement rate in the CSD group than in the intact scar group (t=-4.961 and -3.837, respectively; P<0.001).

CEUS can provide more accurate evidence for uterine scar than TVS, and TIC parameters (peak intensity and enhancement rate) can reflect the microvascular density of uterine scar through the perfusion of contrast agent microbubbles, and evaluate the scar healing. The application of CEUS in the evaluation of cesarean scar has a good prospect.