Improved synthesis and low-temperature autoradiographic evaluation of 18F-n-fluoropropane as a myelin tracer for positron emission tomography.

An improved synthesis of the lipophile 18F-fluoropropane, yielding 30-45 mCi 18F-labelled radiopharmaceutical, is described. The radiochemical yield was 55%-66% determined at the end of a 1-h synthesis. Radiochemical and chemical purity of 18F-fluoropropane was 99% as determined by gas chromatography. Low-temperature autoradiography was used to investigate the lipophile 18F-n-fluoropropane as a myelin tracer for use with positron emission tomography. The white to grey matter ratio based on autoradiograms 12 min after administration of the radiotracer was 2:1, the highest reported to date.