Encephalocele

Overview
Encephalocele, sometimes known by the Latin name cranium bifidum, is a neural tube defect characterized by sac-like protrusions of the brain and the membranes that cover it through openings in the skull. These defects are caused by failure of the neural tube to close completely during fetal development. There have been studies and evidence linking NTD's to folic acid deficiency. The severity of encephalocele varies, depending on the location. Currently, the only effective treatments are reparative surgeries following birth. The degree to which they can be corrected varies greatly on where and how big the encephalocele is.

MRI
(Images courtesy of RadsWiki)