C-11 dimethyloxazolidinedione (DMO): biodistribution, radiation absorbed dose, and potential for PET measurement of regional brain pH: concise communication.

An improved radiochemical synthesis for C-11 dimethyloxazolidinedione (C-11 DMO) makes this agent attractive for the measurement of regional brain tissue pH (rpH) using positron emission tomography (PET). Toward this end, biodistribution data for C-14 DMO in rats at various times after an intravenous bolus injection are reported, together with estimates of radiation absorbed dose for C-11 DMO in man. An error analysis of C-11 DMO PET measurement of rpH indicates that rpH can be determined to within +/- 0.1 pH unit for pH greater than 6.5 with a 20-mCi injected bolus of C-11 DMO, a 30- 45-min equilibration time, and a 15-min PET imaging period.