Abstract:Objective: To evaluate the diagnostic and differential diagnostic value of prenatal ultrasound in annular pancreas (AP). Methods: We retrospectively analyzed the ultrasound images and clinical data of 11 fetuses diagnosed as AP by prenatal ultrasound, summarized the typical signs of AP by prenatal ultrasound and the combined structural malformations of the fetuses, and followed up the clinical outcomes.Results:Of the 11 fetuses, 9 were induced or diagnosed with AP after surgery, and 2 were diagnosed with congenital duodenal atresia after birth.The “double bubble sign”, “paraduodenal pancreatic hypoechoic band” and “clamp sign” were the typical triad of ultrasound manifestations of annular pancreas, There were 10 cases of “double bubble sign”, 9 cases of “paraduodenal pancreatic hypoechoic zone” and 6 cases of “clamp sign”.Conclusions:Fetal annular pancreas has typical prenatal ultrasound manifestations, and the AP triad can be used for diagnosis and differential diagnosis of fetal AP, which is of great clinical value.