Figure 3-3.

MRI multiplanar reconstruction (MPR) in a patient with frontal lobe seizures due to focal cortical dysplasia who had previous MRIs considered as negative. Top row shows nonvolumetric axial T2-weighted and axial and coronal T1-weighted images with 3-mm thickness. The thicker images (3 mm or more) showed areas with blurring of cortex in both frontal regions, indicated by the question marks. The blurred cortex on the right side is a false thickened cortex due to partial volume effect, whereas the area with blurring on the left frontal lobe is a combination of normal partial volume and an abnormal cortex. This small area of focal cortical dysplasia in the left frontal lobe was better demonstrated in the MPR with 1-mm-thick three-dimensional MRI (arrows). MPR allows for more dynamic analyses of MRI with simultaneous view in different planes and orientation of slices. The three smallest images on the right side of the figure depict the coordinates of angulation and location (the two lines on each small image) of the reconstructed images in the other two orientations.The two lines on the small sagittal image indicate the planes of the coronal and axial reconstructed image and so on (the position and angle of these lines of reconstruction can be changed by the examiner allowing a more dynamic analysis of the image). Note the small area with thickened cortex associated with abnormal gyri and a depression on the overlying surface of the brain (also referred to as cortical dimple) (arrows). The T2-weighted and fluid-attenuated inversion recovery (FLAIR) images (not shown) did not show abnormal signal. These changes are suggestive of focal cortical dysplasia type I or IIA.