An improved synthesis of carbon-11 labeled acetoacetic acid and an evaluation of its potential for the investigation of cerebral pathology by positron emission tomography.

1-11C-acetoacetic acid was synthesized by carboxylation of the acetone carbanion. Purification was carried out using HPLC. The product was obtained with a radiochemical yield of up to 58%, corrected for decay, in a total preparation time of 30 min. The distribution of 1-11C-acetoacetic acid after injection into adult Wistar rats and cats was investigated by PET. When the tracer was injected into cats, 3 weeks after inflicting a unilateral freezing lesion upon the brain, accumulation of 1-11C-acetoacetic acid in the ipsilateral brain hemisphere was observed.