Comparison Of Prenatal Diagnostic Value Between Fast Imaging Employing Steady State Acquisition And Single Shot Fast Spin Echo Sequence In Diagnosis Of Placental Invasion

Objective To compare the prenatal diagnostic value and image quality of MRI with fast imaging employing steady state acquisition(FIESTA)and single shot fast spin echo(SSFSE)sequence,in order to provide references for sequence selection of prenatal diagnosis.Methods The MR data of 121 cases with suspected placental invasion were analyzed,the ability to display MR signs associated with placental invasion and image quality were assessed in FIESTA as compared with SSFSE.Compared with the records of cesarean section and pathological finding,sensitivity,specificity,positive predictive values and negative predictive values were calculated.Results The quality of image was significantly higher in FIESTA than in SSFSE(?2=29.74,P=0.000).The ability to display focal interruptions in the myometrial wall was significantly higher in FIESTA than in SSFSE(?2=6.750,P=0.006),and the ability to display abnormalvessel in the placenta(?2=8.471,P=0.020),placental heterogeneity(?2=13.885,P=0.000),intraplacental T2 hypointense bands(?2=4.267,P=0.035)were significantly higher in SSFSE than in FIESTA,while the difference of the efficiency for displaying uterine bulging(?2=0.250,P=0.625),placental recess(?2=0.167,P=0.687),uterine penetration(?2=0.800,P=0.375),placental protrusion sign(?2=0.081,P=0.776)between two sequences had no statistical significance.There were no significant difference of the specificity and positive predictive value among uterine penetration,placental recess,placental protrusion sign between two sequences,all of that were 100%.Conclusions The ability to display the contour and demarcation of placenta and uterus in FIESTA are clearer than those in SSFSE,while the efficiency for displaying the changes of signal in SSFSE is higher than that in FIESTA.The relationship between the placenta and the surrounding structures and whether surrounding tissue is invaded are observed in FIESTA,the signs of placental signal changes were observed in SSFSE,the blood vessels are observed combining two sequences,to hopefully improve the ability of prenatal diagnosis of placenta invasion.