Radiologic analysis of cavum septi pellucidi and cavum vergae in children.

PURPOSE: Cavum septi pellucidi (CSP) and cavum Vergae (CV) are two major midline intracranial fluid collections. They have been in the area of interest for many years because of their variable size during growth. The present study aimed to develop a new classification of CSP, investigate morphometric changes in both the CSP and CV during development, and assess their correlation with well-known cerebral parameters. METHODS: We analyzed MRI scans of 201 pediatric patients. We divided the sample of individuals into five age groups with approximately equal sizes, including only T2-weighted sequences. Three different methods of CSP classification, Nopoulos, Tsutsumi, and ours, newly developed, were considered. RESULTS: We have proposed a new classification of CSP based on the relation between the laminae of the cavum. We observed a very strong correlation (rho = 0.91) between CSP width and length (p < 0.001) but negligible correlations between CSP dimensions and the width of the lateral ventricles (rho < 0.1; p = 0.928). The trends indicate a decrease in CSP size with age (p < 0.001). All cases with present CV were found in patients with laminae CSP completely unadherent (type C, p = 0.001). We have reached almost perfect interrater agreement across measurements. CONCLUSIONS: We have provided a new classification of CSP. It can be considered in every stage of human development as it is not correlated to cerebral diameters. We confirmed no correlation between the width of CSP and the width of the ventricles and biparietal diameter.