Figure 16b. Skull abnormalities. (a) Axial CT image in a patient at age 3 months shows minimal calvarial thickening on the right side. (b) Axial MR image obtained with a fluid-attenuated inversion recovery, or FLAIR, sequence in the same patient at age 8 years shows expansile calvarial lesions with the signal intensity of fat in the frontal and right parietal bones (arrows); a lesion in the right parieto-occipital junction, probably a cavernous vascular malformation (arrowhead); and bilateral abnormalities in periventricular and deep white-matter signal intensities.