[55Co]- and [64Cu]DTPA: new radiopharmaceuticals for quantitative tomocisternography

The diethylenetriaminepentaacetic acid (DTPA) complexes of the convenient half-life positron emitters 55Co and 64Cu have been prepared for quantitation of cerebrospinal fluid (CSF) kinetics in different areas of the brain using positron emission tomography. The radionuclides are prepared by proton bombardment of natural nickel (58Ni(p, alpha)55 Co and 64Ni (p,n)64Cu reactions). The chemical separation of the radionuclides from the target is described, and the production yields, radionuclidic purities and specific activities are given.