Preparation of [1-11C]acetate--an agent for the study of myocardial metabolism by positron emission tomography.

A method of obtaining an injectable solution of acetate labelled in the carboxyl group with the short-lived positron-emitting radionuclide, 11C (t12 = 20.4 min), is described. In the method labelling is achieved via the carbonation of freshly prepared methylmagnesium bromide with 11C-labelled carbon dioxide produced by the 14N(p, alpha)11C nuclear reaction. The method is fast (20 min) and produces sterile, apyrogenic [1-11C]acetate in high radiochemical yield (72 +/- 12%) and in high specific activity (greater than 18.5 GBq/mumol: greater than 0.5 Ci/mumol). The radiochemical purity of the radiopharmaceutical was found to exceed 95% by thin layer and high pressure liquid chromatography. Evidence presented shows that [1-11C]acetate has considerable value as an agent for investigating myocardial metabolism by positron emission tomography.