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We have developed 8‐amino‐3‐(2S,5R‐dimethyl‐1‐piperidyl)‐[1,2,4]triazolo[4,3‐a]pyrazine‐5‐[11C]carbonitrile ([11C]MTP38) as a positron emission tomography (PET) tracer for the imaging of phosphodiesterase 7. For the fully automated production of [11C]MTP38 routinely and efficiently for clinical applications, we determined the radiosynthesis procedure of [11C]MTP38 using [11C]hydrogen cyanide ([11C]HCN) as a PET radiopharmaceutical. Radiosynthesis of [11C]MTP38 was performed using an automated 11C‐labeling synthesizer developed in‐house within 40 min after the end of irradiation. [11C]MTP38 was obtained with a relatively high radiochemical yield (33 ± 5.5% based on [11C]CO2 at the end of irradiation, decay‐corrected, n = 15), radiochemical purity (>97%, n = 15), and molar activity (47 ± 12 GBq/μmol at the end of synthesis, n = 15). All the results of the quality control (QC) testing for the [11C]MTP38 injection complied with our in‐house QC and quality assurance specifications. We successfully automated the radiosynthesis of [11C]MTP38 for clinical applications using an 11C‐labeling synthesizer and sterile isolator. Taken together, this protocol provides a new radiopharmaceutical [11C]MTP38 suitable for clinical applications. [ABSTRACT FROM AUTHOR]

[ Thiocarbonyl -11C]disulfiram ([11C]DSF) was synthesized via iodine oxidation of [11C]diethylcarbamodithioic acid ([11C]DETC), which was prepared from [11C]carbon disulfide and diethylamine. The decay-corrected isolated radiochemical yield (RCY) of [11C]DSF was greatly affected by the addition of unlabeled carbon disulfide. In the presence of carbon disulfide, the RCY was increased up to 22% with low molar activity (A m , 0.27 GBq/μmol). On the other hand, [11C]DSF was obtained in 0.4% RCY with a high A m value (95 GBq/μmol) in the absence of carbon disulfide. The radiochemical purity of [11C]DSF was always >98%. The first PET study on [11C]DSF was performed in mice. A high uptake of radioactivity was observed in the liver, kidneys, and gallbladder. The uptake level and distribution pattern in mice were not significantly affected by the A m value of the [11C]DSF sample used. In vivo metabolite analysis showed the rapid decomposition of [11C]DSF in mouse plasma. [ABSTRACT FROM AUTHOR]