ObjectiveTo explore the significance of ultrasound combined with magnetic resonance imaging (MRI) in the diagnosis of pernicious placenta previa (PPP).MethodsA total of 101 patients with suspected PPP admitted to Chengdu Women’s and Children’s Central Hospital from January 2016 to February 2019 were retrospectively analyzed. The surgical results were used as the gold standard, and the diagnostic value of ultrasound, MRI, ultrasound combined with MRI was compared.ResultsSurgery results showed that among the 101 patients with suspected PPP, 79 patients had positive PPP diagnosis and 22 patients had negative PPP diagnosis. There was no significant difference in the diagnostic sensitivity, negative predictive value, or diagnostic coincidence rate of PPP among ultrasound, MRI, and ultrasound combined with MRI (P>0.05). The diagnostic specificity of the series combination of ultrasound and MRI (86.36%) was higher than that of ultrasound (59.10%), MRI (59.10%), and the parallel combination of ultrasound and MRI (31.32%), and the differences were statistically significant (P<0.05). The diagnostic coincidence rates of abnormal placental attachment of MRI (96.20%) and the parallel combination of ultrasound and MRI (96.20%) were higher than that of ultrasound (87.34%) and the series combination of ultrasound and MRI (87.34%) (P<0.05).ConclusionsUltrasound combined with MRI has a high diagnostic value for PPP. If necessary, ultrasound combined with MRI can be considered to improve the diagnostic efficiency.