Features and diagnostic value of MRI diffusion weighted imaging in placenta implantation

Abstract

Objective To evaluate the features and diagnostic value of magnetic resonance imaging(MRI) diffusion weighted imaging in placenta implantation. Methods 30 patients suspected with placenta implantation were selected.MRI diffusion weighted imaging was applied to examine placenta implantation, pathological diagnosis was used as the gold standard of placenta implantation.The display rate of MRI direct signs and indirect signs in placenta implantation, ADC values in different degree of implanted placenta(adherent placenta, implanted placenta and penetrated placenta) were evaluated.The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy for placenta implantation and Kappa consistence check with pathology were calculated. Results The display rates were all high of direct signs and indirect signs of MRI diffusion weighted imaging in diagnosing placenta implantation.The ADC value of the implanted placenta was higher than that of the adherent placenta, the difference was statistically significant(t=5.216, P=0.001). There was no statistically significant difference in ADC value between the implanted placenta and penetrated placenta(t=1.014, P=0.105). There was no statistically significant difference in ADC value between the non-implanted placenta and adherent placenta(t=1.478, P=0.090). MRI diffusion weighted imaging detected the non-implanted placenta in 7 cases, placenta implantation in 23 cases, while the pathological diagnosis detected the non-implanted placenta in 6 cases, placenta implantation in 24 cases.The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of MRI diffusion weighted imaging in the diagnosis of placenta implantation were 92.00%, 87.50%, 95.65%, 71.43%, 90.00%, respectively.Based on the pathological results, the consistency checking Kappa value of MRI diffusion weighted imaging in diagnosis of placenta implantation was 0.772. Conclusion The display rate of MRI diffusion weighted imaging in diagnosing placenta implantation is high, and it has high clinical value.Application of ADC value can distinguish the degree of placenta implantation. Key words: Placenta accreta; Magnetic resonance imaging