Cortical dysplasia versus dysembryoplastic neuroepithelial tumor in an 18 year old male with seizures.

Sagittal T1-weighted image (A) shows no definite abnormality. Axial T2-weighted FLAIR image (B) demonstrates a subtle focal area of signal hyperintensity within the cortex and subcortical white matter of the left parafalcine parietal lobe(white arrow) with no corresponding restricted diffusion on the axial diffusion weighted trace (C) image. Axial T2-weighted image (D) again demonstrates the hyperintense lesion within the cortex and subcortical white matter of the left parafalcine parietal lobe (white arrow), which is compatible with cortical dysplasia or dysembryoplastic neuroepithelial tumor. This finding is subtle and was not seen prospectively when using the limited sequences. However, the lesion can be seen on the FLAIR images in retrospect. Furthermore, for seizure patients, additional sequences, including isotropic multiplanar sequences, could be added that would help in identifying subtle abnormalities.