18F-FP-(+)-DTBZ is a newly developed nuclear medicine tracer for monoamine transporter. The study purpose is to determine the clinical values of 18F-FP-(+)-DTBZ in the diagnosis of Parkinsonism in patients with carbon monoxide intoxication, regional distribution and its correlation with clinical parameters. This is a three-year prospective research. For each patient, the PET will be arranged twice, with an interval of 18 months. The regional distribuation of 18F-FP-(+)-DTBZ in relation to Parkinsonism severity and regional reduction patterns longitudially will be assessed in order to understand the regional neurotoxicity and the functional progression.