Evaluation Of Fetal Brain Development Based On Fetal Brain Magnetic Resonance In Diameter Measurement

Objective:To investigate diagnostic value of MRI for normal fetal brain development.Materials and methods:This study was approved by the hospital ethics committee and informed consent of the patient.1、According with inclusion and exclusion criteria,to measure the craniocerebral diameters of the fetus in our hospital,which include biparietal diameter(BPD),head circumference(HC),cerebellar area(CA),transverse cerebellar diameter(TCD),fronto-occipital diameter(FOD),length of the corpus callosum(LCC),corpus callosum area(CCA),vermis area(VA),vermis height(VH).In this paper,we analyzed the difference of gestational age distribution in fetal male and female,and analyzed the gender difference in the craniocerebral diameters.Correlation and regression analysis of the mean and gestational age of fetal craniocerebral measurements were conducted.The linear fitting regression equation and quadratic polynomial function fitting regression equation between the main measuring indexes of fetal brain and gestational age(GA)were calculated.(The more R2,the better.).2.In the same inclusion and exclusion criteria,the same scanning apparatus,image selection and measurement method,65 eligible cases of fetal brain image in 2017.11-2018.1 were chosed,defined as Validation group.The numerical values of each measurement index of the brain were measured and the regression equation was used to calculate the gestational age.There was no statistical difference between gestational age evaluation and the actual gestational age of Validation group.The correlation analysis of 9 craniocerebral measurements in the first part of the fetus(defined as the Measurement group)and a stepwise regression analysis was performed.In addition,the brain measurement data of the Validation group was used to obtain the gestational age evaluation value(based on stepwise regression model).There was no statistical difference between the gestational age evaluation value and the actual gestational age of Validation group.3.121 cases of premature infants with brain scanning in our hospital were collected,between 2012.5 – 2017.10.The BPD,CA,TCD,LCC,VA were measured.By substituting the measured values into the stepwise regression equation,the evaluation value of premature infant’s gestational age was obtained.The difference between the evaluation value of premature infant and the actual gestational age was compared.Results:1.657 cases of fetal brain were successfully measured,including 357 male fetuses and 280 female fetuses.There is no statistical difference between male and female fetuses(P = 0.108).So are the craniocerebral diameters(including BPD,HC,CA,TCD,FOD,LCC,CCA,VA,VH).(Male:BPD 80.97±9.41 mm,FOD98.36±10.72 mm,HC 291.5±32.46 mm,LCC 31.53±3.86 mm,CCA 141.27±31.1mm2,VA 692.64±243.27 mm2,TCD 39.68±7.01mm;Female: BPD 79.91±8.92 mm,FOD96.98±9.34 mm,HC 286.72±29.14 mm,LCC 31.53±3.46 mm,CCA 142.21±33.89mm2,VA 238.34±75.86mm2,TCD39.91±6.81 mm,P > 0.05).The measured values of the normal fetal craniocerebral diameter increases with the growth of gestational age.The best fitting regression equation and correlation coefficient of the measuring index and gestational age are as follows: BPD =-0.052*GA 2 + 5.340*GA-34.70(R2 =0.742,P < 0.01)、FOD =-0.079*GA 2 + 7.197*GA-49.40(R2 = 0.762,P <0.01)、HC =-0.227 *GA 2 + 21.08* GA-146.2(R2 = 0.753,P < 0.01)、LCC=-0.034* GA2 + 2.916* GA-25.41(R2 = 0.661,P < 0.01)、CCA =-0.363* GA2+ 26.97* GA-342.6(R2 = 0.332,P < 0.01)、VH =-0.003 *GA 2 + 1.055* GA-9.934(R2 = 0.695,P < 0.01)、VA = 0.285* GA2 + 0.025 *GA-54.80(R2 =0.757,P < 0.01)、TCD=-0.002 *GA2 + 1.834* GA-15.56(R2 = 0.839,P <0.01)、CA= 1.395 *GA 2-28.30* GA + 179.8(R2 = 0.844,P < 0.01)。2.In the Validation group,49 cases were successfully measured.There was a statistical difference between the LCC of gestational age evaluation value in the Validation group(30.93 + + 4.02)and the actual gestational age(32.69 + 3.06)(P < 0.05).So was the CCA of gestational age evaluation value(28.44 + 3.45).The BPD of gestational age evaluation value(32.15±3.26)、the OFD of gestational age evaluationvalue(32.81±3.51)、the HC of gestational age evaluation value(33.59±4.28)、the VA of gestational age evaluation value(32.51±3.59)、the VH of gestational age evaluation value(31.94±4.06)、 the CA of gestational age evaluation value(32.63±3.57)、the TCD of gestational age evaluation value(32.69±3.06),There was no statistical difference between the gestational age evaluation and the actual gestational age of the Validation group.Based on the measured values of each diameter of fetal brain in the Measurement group,the stepwise regression equation of the gestational age and the diameter of the fetal brain is GA=11.4135+0.0623*BPD+0.1179*LCC+0.0078*VA+0.0039*CA+0.1728*TCD(R squared = 0.8747,P < 0.01).There was no statistical difference between the gestational age evaluation of the Validation group(based on stepwise regression model,32.44±2.79)and the actual gestational age of the Validation group(32.69±3.06)(t =0.083,P = 0.934).3.96 premature infants were successfully measured.The assessment of premature infants(34.29±1.95)were less than the actual gestational age(35.02±1.54),and the difference between them was statistically difference.(P =0.002)Conclusion: This study showed that fetal craniocerebral measurements were positively correlated with changes in gestational age.The fitting quadratic polynomial function curve can reflect the relationship between the measuring index and the gestational age.Using the regression relations between the gestational age and the BPD,LCC,VA,TCD,CA can quickly and accurately to assess fetal gestational age.The stepwise regression equation between the main measuring index and the gestational age was established to provide a new imaging evaluation method for the brain development of premature infants.