ABSTRACT
Objective To evalute the clinical significance of the Oblique view of three-dimensional ultrasonography(3DUS) in diagnosis of the fetal cavum septum pellucidum(CSP) malformation.Methods Thirty-eight cases of fetuses with the CSP malformation,found originally by trans-abdominal two dimensional ultrasonography(2DUS),were scanned using Oblique of trans-abdominal 3DUS.The results were compared with MRI inspection and post-natal follow-up.Results Thirty-eight fetuses suspected with 3DUS Oblique were fully confirmed by autopsy and MRI,the distribution of CSP malformation included:①Twenty-one cases with absence of septum pellucidum(ASP),among them 10 cases with isolates of septum pellucidum,1 case with septooptic dysplasia(SOD),10 cases with agenesis of corpus callosum(9 complete agenesis of corpus callosum and 1 partial agenesis of corpus callosum.②Twelve cases with shrinkage of them 9 simple shrinkage and 3 partial agenesis of corpus callosum respectively.③ Five cases with enlargement,all of which also with increasing sizes of cavum vergae.Thirty-five cases are consistent with MRI observations.The diagnosis consistency differences between both methods were not significant.Conclusions 3DUS Oblique view can reveal the structure of fetal cavum septum pellucidum and corpus callosum clearly,which enable more accurate prenatal counseling and boild firm base for further diagnosis.