Simultaneous PET and MR imaging of the human brain

Abstract

Complementary anatomical and functional information obtained from separately performed magnetic resonance imaging (MRI) and positron emission tomography (PET) examinations have long been combined either by performing a parallel analysis or by using software co-registration techniques to merge the two datasets. However, a major assumption that has been made in these cases is that no changes in underlying conditions have occurred between the two studies; increasingly investigators are recognizing that this is not the case, particularly when assessing a subject's mental state, which may change on the order of seconds, but also in some diseases such as acute ischemic stroke where physiological and metabolic changes can occur on the order of minutes. As we probe illnesses of the mind more thoroughly, the state of the mind and the state of the brain at any given instant become more relevant.