The Value Of Three-dimensional Ultrasound In Diagnosis Of Placenta Accreta During The First Trimester

Objective:To investigate the diagnostic value of three-dimensional ultrasound in placenta accerta（PA）during the first trimester.Methods:A total of 58 pregnant women who underwent prenatal ultrasound during early pregnancy(11-13⁺⁶weeks)and had at least one history of cesarean section or intrauterine operation were selected as subjects.Not only conventional ultrasound including Two-dimensional gray-scale ultrasound and two-dimensional color Doppler ultrasound but also three-dimensional ultrasound including ultrasound tomography（TUI）and three-dimensional energy Doppler ultrasound（3D PDUS）were used in their prenatal examination.The clinical data and ultrasound signs were analyzed retrospectively,4Dview software was used to calculate 3D PDUS vascular indices including vascularization index（VI）,blood flow index（FI）,vascularization-blood flow index（VFI）,and ROC curve was utilized to evaluate the diagnostic capability of 3D PDUS vascular indices.Then,the subjects were divided into PA group and non-PA group on the basis of clinical and pathological results,and the differences of clinical data,ultrasound signs and 3D PDUS vascular indices were compared between the two groups.Furthermore,the PA group was divided into placenta accreta（PC）and severe invasive placenta（s PA）including placenta increta（PI）and placenta percreta（PP）,and the differences in ultrasound signs and 3D PDUS blood flow parameters between the two groups were compared.Finally,the diagnostic value of conventional ultrasound and three-dimensional ultrasound was compared and of three-dimensional ultrasound in different types of PA was analyzed.Results:22 PA consisted of 12 PC and 10 s PA were confirmed by clinical or pathology,and 36 cases were non-PA.The age（>35）,placenta previa,history of cesarean section and intrauterine operation,gestational age,bleeding volume and the rate of hysterectomy were statistically different（P<0.05）between the two grounps.The conventional ultrasound signs including loss of clear zone,subplacental hypervascularity,abnormal placental lacunae and thin retroplacental myometrium（≤4.4mm）were different between the two groups（P<0.05）.The thin retroplacental myometrium had the highest diagnostic Accuracy（74.13%,74.13%,70.68%vs 81.03%）,what’s more,subplacental hypervascularity and abnormal placental lacunae made scense for classifying PA,and the diagnostic accuracy of abnormal lacunar space was higher（81.82%vs 72.73%）;and the diagnostic accuracy of TUI was higher than conventional ultrasound（79.31%vs 74.13%）.The VI,FI and VFI in PA group were higher than non-PA group（P<0.05）,and the diagnostic ability（AUC:0.86 vs 0.80,0.71）and accuracy（82.75%vs 75.86%,72.41%）of VFI was higher than VI and FI when VFI>10.1,furthermore,VI and VFI were statistically different between PC and s PA（P<0.001）,and VFI had higher ability（AUC:0.93 vs 0.86）and accuracy（91.37%vs 87.93%）in diagnosing s PA when VFI>11.67.The sensitivity,specificity and diagnostic accuracy of conventional ultrasound in diagnosing PA were86.36%,66.67%and74.13%,respectively,those value of three-dimensional ultrasound were 96.79%,75.12%and 82.75%.Conclusions:Loss of clear zone,subplacental hypervascularity,abnormal placental lacunae and thin retroplacental myometrium were significant signs for diagnosing PA in early pregnancy,and the sign of thin retroplacental myometrium（≤4.4mm）had highest diagnostic accuracy,moreover,the subplacental hypervascularity and abnormal placental lacunae had a certain significance for classifying PA,and the diagnostic accuracy of the abnormal placental lacunae was higher;TUI was superior to conventional ultrasound in detecting signs,and its diagnostic accuracy of PA was higher than conventional ultrasound;3D PDUS vascular indices had great value in the diagnosis of PA and s PA,therefore,it was more reliable to diagnose PA when VFI>10.08 and it also had a good performance in diagnosing s PA when VFI>11.67;In summary,the diagnostic and screening ability of three-dimensional ultrasound was obviously higher than conventional ultrasound in diagnosing PA during the first trimester,so three-dimensional ultrasound could provide more instructive informations for clinical diagnosis and treatment.