Recently we have clinically used three new radioligands, [11C]SA4503, [11C]MPDX, and [11C]TMSX, for mapping sigma1, adenosine A1, and adenosine A2A receptors, respectively, in the human brain by positron emission tomography. These radioligands are synthesized by methylation of the respective demethyl precursor with [11C]methyl iodide. Here we demonstrate the improved syntheses of these compound...

The development of a novel electrochemical methodology to generate carbon-11 carbon monoxide ([11C]CO) from cyclotron-produced carbon-11 carbon dioxide ([11C]CO2) using Ni(cyclam) and Zn(cyclen) complexes is described. This methodology allows up to 10% yields of [11C]CO from [11C]CO2. Produced [11C]CO was subsequently converted to [11C]N-benzylbenzamide under mild conditions with a radiochemica...

BACKGROUND Using positron emission tomography (PET), we compared two tracers, [11C]metomidate ([11C]MTO) and [11C]acetate ([11C]ACE), for the characterization of hepatic tumors. METHODS Thirty-three patients underwent PET with [11C]MTO and [11C]ACE and magnetic resonance imaging (MRI). Based on the histology of the tumor biopsy, 14 patients had hepatocellular carcinoma (HCC), 9 patients had f...

Background [11C]Cimbi-36 is a serotonin 2A receptor agonist positron emission tomography radioligand that has recently been examined in humans. The binding of agonist radioligand is expected to be more sensitive to endogenous neurotransmitter concentrations than antagonist radioligands. In the current study, we compared the effect of serotonin releaser fenfluramine on the binding of [11C]Cimbi-...

We prepared 11C-labeled 5-(4-chlorophenyl)-1-(4-methoxyphenyl)-3-(trifluoromethyl)-1H-pyrazole ([11C]1) and 4-[5-(4-methoxyphenyl)-3-trifluoromethyl-1H-pyrazol-1-yl]benzenesulfonamide ([11C]2) for imaging COX-1 and COX-2 isoforms, respectively, by positron emission tomography. [11C]1 and [11C]2 were synthesized in high radiochemical yields by O-[11C]methylation with [11C]methyl triflate in acet...

In the early 1990s, 9-(+)-11C-dihydrotetrabenazine (9-(+)-11C-DTBZ) was shown to be a useful positron emission tomography (PET) imaging agent for various neurodegenerative disorders. Here, we described the radiosynthesis and evaluation of the 9-(+)-11C-DTBZ analog, 10-(+)-11C-DTBZ, as a vesicular monoamine transporter 2 (VMAT2) imaging agent and compare it with 9-(+)-11C-DTBZ. 10-(+)-11C-DTBZ w...

Synthesis of 11C-labeled capsaicin ([11C]-2) was accomplished by O-[11C]methylation with [11C]methyl iodide to a corresponding catechol precursor (1). In vivo whole-body distribution of [11C]-2 in rats was investigated by positron emission tomography after intravenous injection. The results showed that [11C]-2 accumulated in the brain and body surface, which was closely associated with the expr...

Objective(s): This study aimed to compare the diagnostic values of 11C-choline and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in patients with cholangiocarcinoma (CCA). Methods: This prospective study was conducted on 10 patients (6 males and 4 females), aged 42-69 years, suspected of having CCA based on CT or magnetic resonance imaging (MRI) resu...

The localization of quaternized muscarinic receptor (mAChR) antagonists, [11C]methyl tropanyl benzilate ([11C]MTRB) and [11C]methyl quinuclidinyl benzilate ([11C]MQNB), in rat pituitary was compared to that of [11C]tropanyl benzilate ([11C]TRB), a neutral antagonist. The quaternized ligands localize via a mAChR-mediated mechanism as shown by 60% reduction in radioactivity concentrations in the ...