The Value Of Ultrasonography And Magnetic Resonance Imaging In Diagnostic Fetal Ventriculomegaly And Exploration Of A New Method For Evaluating The Degree Of Expansion

Background Fetus with ventriculomegaly is one of the most common problems found in prenatal ultrasound,which may be related to abnormalities of the central nervous system.The degree of dilatation is the key to assessing the prognosis of the fetus.Fetal with mild ventriculomegaly without other abnormalities may be normal anatomical structural variations,and It’s most probability to be a normal baby after birth;when the lateral ventricle dilatation is moderate and severe degree,the fetus may be related to other central nervous system abnormalities.Accurately grading fetal ventriculomegaly and assessing whether it is complicated with intracranial structural abnormalities are significant for doctor to give pregnant woman advice in treatment,prognosis and consult.Ultrasonography and magnetic resonance image are the main method of fetal imaging,the accuracy of diagnosing lateral ventricle expansion with intracranial abnormalities is also controversial.Domestic and foreign studies have shown that in the diagnosis of fetal central nervous structure abnormalities,MRI found the structural abnormalities but not detected by prenatal ultrasound in the range of 5% to 50%.Therefore,it is necessary to conduct a comparative analysis of ultrasound and MRI in diagnosing fetal lateral ventricle dilatation.Some domestic and foreign studies explore the relationship and value of lateral ventricle development and neurodevelopment by observing the structures around the ventricle.There are many parameters for evaluating the lateral ventricle,including the measurement of the anterior horn,posterior horn,and triangular area of the lateral ventricle.Some studies evaluate the extent of lateral ventricle expansion by observing the structures around the ventricle.Studies have shown that the display of calcarine sulcus is related to lateral ventricle dilatation,which is helpful for the diagnosis and prognosis of ventriculomegaly.There are many studies have shown that the display of the calcarine sulcus on MRI is related to the neurodevelopment of the fetus after birth.Exploring the clues of the degree of lateral ventricle expansion and fetal brain development is the focus of research at this stage.Our purpose is to explore whether there is a correlation between them and provide clues for the discovery of abnormal cortical development.Objective 1.To evaluate the consistency of the result of fetus with ventriculomegaly between the prenatal ultrasound and fetal MRI.2.To explore the possible association between unilateral,bilateral or asymmetric ventriculomegaly with other fetal central nervous system abnormalities.3.In order to improve the diagnostic ability of MRI on fetus with ventriculomegaly,we compare the ultrasound and MRI of fetal ventriculomegaly with intracranial abnormalities.4.To measure and analyze the parenchyma thickness of the fetal lateral ventricle and medial occipital lobe of posterior horn of lateral ventricle by MRI.MethodsPart 1: Diagnostic Value of Ultrasound and MRI for Fetal ventriculomegaly Methods : Select data From June 2018 to October 2020,at the Guangzhou Women’s and Children’s Medical Center,.There are 78 cases of fetal,122 dilated lateral ventricles.The pregnant women were examined both by ultrasound and MRI.Record the diagnostic results of ultrasound and MRI images,including the measured value of the lateral ventricle,whether it is combined with abnormal brain structure,and the type of abnormal brain structure.The data obtained wasstatistically processed with IBM SPSS23.0 software,In line with the normal distribution,the mean ± standard deviation is used to indicate,Qualitative data is expressed in frequency and percentage.Kappa coefficient and was used to evaluate the consistency of the two methods.Categorical variables should be inferred by chi-square test.P<0.05 indicates that the difference is statistically significant.Part 2: MRI analyzes the relationship between the fetal ventriculomegaly and the thickness of the medial occipital lobe of the posterior horn of the lateral ventricle.Methods: Select data fetus undergoing MRI,103 fetuses were selected as the lateral ventricle expansion group,and 78 normal lateral ventricles were the control group.Choose the T2-weighted cross section of MRI to show the clearest of the parenchyma thickness of the medial occipital lobe of posterior horn of lateral ventricle,and the thickness of the cortex is measured,measured the thinnest part.The data obtained was statistically processed with IBM SPSS23.0 software.Before statistics,use the moment method to test the normality of quantitative data and homogeneity of variance test,and the mean is used for normal distribution standard deviation((?)x±s)means that continuous variables of non-normal distribution are described by median and interquartile range.Univariate analysis of variance was used for the comparison of multiple sample means.P<0.05 indicates that the difference is statistically significant.Results1.When comparing the consistency of the measured values by the two methods according to the evaluation method of mild,moderate and severe and the kappa coefficient,it shows that the consistency is good.2.There are 78 cases of fetuses with ventriculomegaly,70 cases were diagnosed the same results on ultrasound and MRI images,and 8 cases were not.3.Bilateral symmetrical ventriculomegaly combined with intracranial structural abnormalities is more likely than unilateral ventricular dilatation combined with intracranial structural abnormalities.The difference was statistically significant(P<0.05).4.The parenchyma thickness of the medial occipital lobe of posterior horn of lateral ventricle is highly positively correlated with the gestational age of the fetus;and the parenchyma thickness of the medial occipital lobe of posterior horn of lateral ventricle in the fetal ventriculomegaly is negatively correlated with the degree of lateral ventricular expansion.The parenchyma thickness of the medial occipital lobe of posterior horn of lateral ventricle in fetal ventriculomegaly is relatively thin,especially with moderate to severe lateral ventricle dilatation.Conclusions1.There is no significant difference between ultrasound and MRI in measuring the width of the left and right lateral ventricles of the fetus;MRI has it’s advantages in fetus ventriculomegaly of prenatal diagnosis,Combined ultrasound and MRI can help improve the accuracy of imaging diagnosis.2.When a fetus with lateral ventricle dilatation is encountered,it should be checked in detail for intracranial structural abnormalities,especially for fetuses with bilateral lateral ventricle dilatation.3.The parenchyma thickness of the medial occipital lobe of posterior horn of lateral ventricle increases with the increase of gestational age;The higher the degree of lateral ventricle dilatation,the thinner the brain parenchyma of the medial occipital lobe of posterior horn of lateral ventricle.