The Value Of Prenatal Diagnosis Of Fetal Central Nervous System Abnormality By MRI Based On Ultrasound

Background: Abnormal fetal central nervous system(CNS)is a common clinical fetal malformation disease,with high disability and fatality,and serious harm.Accurate diagnosis of fetal CNS abnormalities is of great significance,and can guide clinical science to formulate intervention measures,reduce the incidence of severe CNS abnormalities after birth,and minimize their harm.At present,ultrasonography is the preferred method for the diagnosis of fetal CNS abnormalities,but there is still controversy over whether MRI is necessary on the basis of ultrasonography.Objective: To explore the influence of MRI examination based on ultrasonography on the diagnosis of abnormal fetal CNS,and to analyze the necessity of MRI examination based on ultrasonography.Methods: From April 2019 to December 2021,100 pregnant women with mid-to-late pregnancy who were diagnosed with abnormal craniocerebral development,suspected CNS abnormality and continued pregnancy were selected by ultrasonography.months(death after birth were followed up until death).The results of postnatal diagnosis were used as the basis for clinical diagnosis,and the results of ultrasonography and MRI on the basis of ultrasonography were analyzed.The following indicators were observed(1)imaging quality score of ultrasound and MRI;(2)diagnostic accuracy,sensitivity,specificity,missed diagnosis and misdiagnosis rate of ultrasound and MRI;(3)MRI supplemented ultrasound diagnosis,MRI corrected ultrasound diagnosis(4)ROC curve was used to analyze the diagnostic performance of MRI based on ultrasound;(5)ADC values and SWI corrected phase values were compared between abnormal lesions in the central nervous system and normal control areas.Results:(1)After follow-up and postnatal screening,65 cases were diagnosed with abnormal CNS.(2)There was no statistical difference between ultrasound images and MRI image positioning quality scores(P>0.05).The quality scores of blood flow display and choroid plexus ependyma display in MRI images were lower than those in ultrasonography,and the difference was statistically significant(P<0.05).(3)The diagnostic accuracy,sensitivity,and specificity of MRI(95.00%,96.92%,91.42%)were higher than those of ultrasonography(74.00%,75.38%,71.43%),and the rate of missed diagnosis and misdiagnosis(3.08%,8.57%))was lower than that of ultrasonography(24.62%,28.57%),and the difference was statistically significant(P<0.05).(4)Among the 65 cases of fetal CNS abnormality,52 cases of MRI examination results were completely consistent with the ultrasonography examination,the agreement rate was 80.00%(52/65).MRI examination supplemented 5 cases of ultrasound examination results,and the supplementary diagnosis rate was 7.69%(5/65);MRI examination corrected 6 cases of ultrasound examination results,and the corrected diagnosis rate was 9.23%(6/65);MRI examination missed 2 cases of small arachnoid Cysts were accurately diagnosed by ultrasonography,with a missed diagnosis rate of 3.08%(2/65).(5)The AUC of ultrasound and MRI in diagnosing abnormal fetal CNS was0.915,which was higher than that of ultrasound examination alone(0.695)and MRI examination alone(0.879).(6)The ADC value of abnormal CNS lesion area was lower than that of non-lesion area,and the SWI-corrected phase value was higher than that of non-lesion area,and the difference was statistically significant(P<0.05).Conclusion: Ultrasound examination and MRI examination have their own advantages and disadvantages in the diagnosis of fetal CNS abnormality.MRI examination based on ultrasonography can complement each other and improve the accuracy of fetal CNS abnormality diagnosis.It has good application value and is recommended to be promoted.