We hypothesize that quantitative measurements of the beta cell mass within the endocrine pancreas can be obtained by PET via targeting of vesicular monoamine type 2 transporters with the radioligand [11C]DTBZ. and that there will be significant differences in [11C]DTBZ uptake in the anatomical space of the pancreas between normal individuals and those with BCM predicted to be greater or less than normal based on the measurement of insulin secretion.