ON THE COVER

This whole-body PET image of a healthy male volunteer shows that most of the radioactivity is distributed in the urinary bladder, indicating prompt excretion through the renal system. Renal pelvis, stomach, salivary glands, liver, kidneys, spleen, and vertebral column were also clearly visualized. However, uptake in myocardium, pancreas, and lungs was low. The distribution of ¹¹C-MP4B in the brains of patients with Alzheimer's disease appears to be in accordance with the distribution of butyrylcholinesterase seen in postmortem studies of human brain, except for an observed higher activity in striatum than in cortex.