MRI differetial diagnosis of posterior fossa cyst with hydrocephalus in children / 实用放射学杂志

ABSTRACT

Objective To study MRI diagnosis and differential diagnosis of posterior fossa cyst with hydrocephalus in children. Methods MRI performances and clinical data of 56 children with cyst in the posterior fossa and hydrocephalus were analyzed and classified.Results 12 cases of Dandy-Walker malformation(DWM)showed absence of the vermis at different degrees and the enlarged fourth ventricle widely communicating with the large posterior fossa cyst,accompanied by elevation of the tentorium cerebella and hydrocephalus,in which 1 case combined with callosal agenesis,1 case with subependymal gray matter heterotopia and 1 case with subependymal gray matter heterotopia and small occipital encephalocele.9 cases of Blake's pouch cyst(BPC)showed mildly dilatation of the fourth ventricle,and the cyst was below the cerebellar and hydrocephalus.Neither cerebellar hypoplasia nor elevation of the tentorium cerebella was observed. The postirior wall of the cyst was observed on sagittal T 2WI in 5 cases.The choroid plexus of the fourth ventricular moving to the top wall of the cyst were seen on thin sagittal T 2WI in 1 case.35 cases of arachnoid cyst(AC)showed aggregation of cerebrospinal fluid,and the fourth ventricular and aqueductal stenosis at different degrees and hydrocephalus.Conclusion MRI has evident advantages at diagnosis and differential diagnosis of cystic malformations of the posterior fossa with hydrocephalus,especially on sagittal MRI.