polymicrogyria usually gets misdiagnose with pacygyria so therefore it needs to be distinguished from pachygyria. pachygyria is a distinct brain malformation in which the surface folds are excessively broad and sparse. pachygyria and polymicrogyria may look similar on low-resolution neuroimaging such as ct because the cortical thickness can appear to be increased and the gyri can appear to be broad and smooth in both conditions. this is why higher resolution neuroimaging are needed such as an mri.