Carbon-11 is cyclotron- produced radionucide. Cyclotron products are important for nuclear medicine because of the high photon/ particle energies that are from Beta plus and Electron Capture decay. Because of Carbon-11's short half-life, this positron emmiting radionuclide must be prepared on site with a biomedical cyclotron. Because of its high cost of the biomedical cyclotron, at first the use of it was limited but today there are many cyclotrons making short-lived positron emiiting radionuclides for nuclear medicine imaging.