A study published in the Archives of General Psychiatry that used PET to measure microglial activation in the brains of young men with autism spectrum disorder found the patients' brains showed significantly higher binding potential values in the cerebellum, midbrain and other areas. Another study published in the same journal that used MRI to measure brain cortical volume found that young men with the disorder had significantly higher cortical thickness within the frontal lobe regions. The findings indicate that young men with ASD have variations in brain surface anatomy and more brain immune activation.