Ultrasound Evaluation Of Corpus Callosum Development In Normal Fetuses During Middle And Late Pregnancy

Objectives Application of prenatal ultrasonic abdominal scan of middle-late pregnancy fetal craniocerebral midline sagittal section each part of the development situation of corpus callosum,and establish the normal reference value range,all parts of the corpus callosum analysis development rule of the various parts of the corpus callosum and make early warning for the early diagnosis of corpus callosum dysplasia,for clinical provides a feasible corpus callosum dysplasia screening method,provide the basis for early treatment and prevention.Methods A total of 867 single pregnant women with a gestation age of 20⁺⁰-35⁺⁶weeks and a clear and complete display of corpus callosum in the midline agnostic section of fetal brain were selected to undergo routine ultrasound examination in the Department of Ultrasonography of our hospital from November 2019 to October 2020.The corpus callosum was measured with a GE Voluson E8 and E10 ultrasound diagnostic instrument with a Two dimensional ultrasonic convex array probe.Display plane:central sagittal view of the fetal brain.The Length of the corpus callosum（LCC）,the mouth Thickness of the rostum（RT）,the knee Thickness of the Genu（GT）,the body Thickness of the body（BT）and the pressure Thickness of the splenium（ST）were measured.Statistical method:SPSS25.0 software was used for statistical analysis of the above data.Measurement data were represented as mean±standard deviation or median,and all data were considered statistically significant if P<0.05:50 cases were randomly selected for reproducibility test of the two subjects;The normal reference ranges of the parameters of corpus callosum in the midsagittal section of fetal craniocerebral were established in a group of eight(20⁺⁰-21⁺⁶weeks,22⁺⁰-23⁺⁶weeks,24⁺⁰-25⁺⁶weeks,26⁺⁰-27⁺⁶weeks,28⁺⁰-29⁺⁶weeks,30⁺⁰-31⁺⁶weeks,32⁺⁰-33⁺⁶weeks,34⁺⁰-35⁺⁶weeks)ever two weeks,and the measured values of corpus callosum in the eight groups were evaluated completely.Scatter plots of parameters of corpus callosum and gestational age were plotted,and correlation and regression analysis were conducted,and regression equations were established.Results 1 The median sagittal display rate of corpus callosum was closely related to fetal position:78.31%in the breeches or transversals,21.68%in the cephalic position.2 There was no significant difference in corpus callosum between the two groups（P>0.05）.3 The percentile method was used to establish the normal reference ranges of eight groups:95%reference ranges of corpus callosum length were 17.855-23.235mm,20.922-28.565mm,25.275-32.150mm,29.560-34.780mm,31.803-38.060mm,34.000-39.820mm,37.072-42.897mm,38.660-45.205mm;The 95%reference values of the mouth thickness of corpus callosum were 0.800-1.300mm,1.100-1.665mm,1.300-1.700mm,1.400-1.900mm,1.400-1.877mm,1.360-1.700mm,1.400-2.000mm,1.400-2.090mm.The 95%reference range of the knee thickness of corpus callosum was 1.600-2.395mm,1.935-3.000mm,2.400-3.200mm,2.500-3.500mm,2.600-4.200mm,3.000-3.600mm,3.300-4.400mm,2.865-4.580mm.The 95%reference range of corpus callosum body thickness was 1.110-2.200mm,1.700-2.100mm,1.600-2.200mm,1.700-2.280mm,1.600-2.300mm,1.600-2.140mm,1.700-2.300mm,1.610-2.400mm.The 95%reference range of the barbic thickness of corpus callosum was 1.555-2.695mm,2.100-3.000mm,2.200-3.200mm,2.600-3.700mm,2.600-3.500mm 2.700-3.700mm,2.800-4.155mm,2.600-4.060mm.4LCC,RT,GT,BT and ST were significantly correlated with gestational age（P<0.01）.The correlation coefficients were 0.975,0.703,0.909,0.368 and 0.817,respectively.Quadratic regression equations with good fit between each parameter and gestational age were established.The regression relationship between all the measured parameters and gestational age was statistically significant（P<0.05）.5 Thickness of the corpus callosum before 24 weeks,the corpus callosum developed rapidly and then slowly,with a similar pattern of growth in knee and compression thickness,characterized by progressive growth throughout gestation.The growth rate of corpus callosum length was stable and progressive.Conclusions 1 The median sagittal section of the fetal brain can be used to observe and evaluate the condition of the corpus callosum in detail.Ultrasound is a good tool for detecting the corpus callosum of the fetus,and understanding the normal growth pattern is helpful to distinguish normal and abnormal corpus callosum development.2 20⁺⁰-35⁺⁶weeks fetal corpus callosum parameters are significantly positive correlation with gestational age.The normal reference range of each parameter on the median sagittal section can provide reference for prenatal ultrasound assessment of corpus callosum and basis for prenatal screening of abnormalities of corpus callosum.3 The normal values of the length and thickness of the corpus callosum can be obtained by measuring the corpus callosum in a standardized midsagittal section of the fetus,which can be used as an index for clinical judgment of the size of the corpus callosum of the fetus.Figure 8;Table 8;Reference 76...