A fluorodeoxyglucose (FDG) PET image fused to an MRI scan of a patient with a left superior oblique palsy. He fixated with the paretic left eye, which caused continuous activation of the left inferior rectus muscle to compensate for the left hypertropia. This can be seen as a hot spot (red) in the inferior medial left orbit. See Li and colleagues, pages 160–161 in this issue, for details.