PET Scans, Visualized by Lavoisier
Brain imaging. It was anticipated as far back as the 18 th century by Lavoisier , writes Stanislas Dehaene in Reading in the Brain ! Lavoisier noticed that an organ uses more energy when it is at work than when it is at rest. Shouldn’t the same principle apply to the brain, wrote Lavoisier: “One can evaluate… how many pounds of weight correspond to the efforts of a man who recites a speech… One might even assess the mechanical content in the work of a philosopher as he thinks.” It would take another 200 years before this “simple idea” could be put into practice. Via what we call a PET scan, which stands for Positron Emission Tomography. It involves the injection of a small amount of radioactive water, where the normal Oxygen 16 has been replaced by its isotope Oxygen 15 . This water spreads over the entire body quickly via the blood. In the brain in particular, radioactivity accumulates in regions where blood flow is the fastest, which are the same regions where brain ...