Fig. 16

45-year-old woman with an episode of seizure. On axial turbo spin echo (TSE) T2-w. image a two almost imperceptible areas of linear hypointensity can be noted (arrow shows the most prominent in the parietal lobe). Axial susceptibility weighted imaging (SWI) scan at the same level (b) shows evident susceptibility artifacts caused by hemosiderin within small vascular malformations. The same artifacts can also be noted in echo-planar imaging (EPI) diffusion-weighted image with a b-value of zero (c). EPI sequence sensitivity to susceptibility artifact is well depicted by comparison between TSE T2-w. e and EPI image (f) of the brain in a patient with a ferromagnetic dental device