Prenatal MRI diagnosis of fetal midline dural sinus malformation / 中国医学影像技术

ABSTRACT

Objective To explore prenatal MRI findings of fetal midline dural sinus malformation(DSM).Methods Eleven fetuses of midline DSM were collected.Abnormalities in the fetal occipital or cerebellar area were found from 21 to 27 weeks of gestation.Then MR scanning in the following week was performed.Of all 11 fetuses,9 were pathologically proved to be midline DSM,and the other 2 were followed up and proved after birth.The imaging findings and pathological features were analyzed.Results MRI of 11 fetuses showed cystic dilation of the occipital cranium of torcular herophili area,with the size of 10 mm× 15 mm to 35 mm× 55 mm,and the adjacent sinuses were also dilated.On axial or coronal images,the lesions were cuneiform,while on sagittal images,the lesions were spindle-or crescent-shaped.The lesions displayed isointensity or slightly hyperintensity on T1WI,while slightly hypointensity,isointensity or slightly hyperintensity on T2WI.In 9 of the 11 fetuses,class round or bar thrombosis on the side wall of the cystic mass were observed,which were hyperintensity on T1WI and isointensity and hypointensity,isointensity or hyperintensity on T2WI.Hemosiderin deposition was observed around the thrombi in 6 fetuses.Lesion diameters in 2 fetuses were more than 30 mm,and the adjacent brain tissue was significantly dislocated.Nine fetuses of postmortem pathology after induced labor showed deformed and dilated venous sinuses,in which eccentric thrombi were seen in 7 fetuses with side branches around them.Normal brain development was observed in 2 live birth newborns.Conclusion Prenatal MRI can accurately diagnose fetal midline dural sinus malformation,and estimate the development of fetal brain,which may be helpful to prognosis prediction.