Parkinsonian syndromes are considered clinicopathological conditions that are challenging to diagnose. Molecular imaging with [18F]-FDOPA and [18F]-FDG contributes to a more accurate clinical diagnosis by evaluating presynaptic dopaminergic pathways and glucose metabolism, respectively. The aim of this study was to correlate diagnoses made from dual PET/CT with the initial clinical diagnoses, as well as during follow-ups in patients with Parkinsonian syndromes. A secondary objective was to describe the imaging findings. Methods: A total of 150 patients with a clinical diagnosis of neurodegenerative Parkinsonism were evaluated using dual PET/CT. Clinically, 82% were diagnosed with PD, while the remaining 18% had an atypical Parkinsonism. Results: Using dual PET/CT, the most frequent diagnosis was PD in 67% of the patients, with the rest being diagnosed with an atypical Parkinsonism. In an agreement analysis between the initial clinical diagnosis and the imaging diagnosis by dual PET/CT, a concordance of 94.1% (n = 95) was observed for PD. In the remaining patients, the clinical diagnosis differed from that suggested by dual PET/CT, with atypical Parkinsonian syndromes being diagnosed as DLB in 40% (n = 4), PSP in 46.7% (n = 7), MSA-C in 75% (n = 6), MSA-P in 70% (n = 7), and CBD in 66.7% (n = 4). A total of 38.66% (n = 58) of patients were followed up (median follow-up of 27 months), with a Kappa coefficient of 0.591 (p < 0.001), suggesting substantial agreement. Conclusions: Dual FDOPA–FDG PET/CT demonstrated moderate agreement with the initial clinical diagnosis of Parkinsonism and moderate to substantial agreement during follow-up. This dual technique, therefore, stands out in differentiating between types of Parkinsonisms.

Metronidazole is a widely prescribed antibiotic used for treating bacterial and protozoal infections. Neurological complications from metronidazole are rare, but they have been associated with several syndromes, including cerebellar syndrome, encephalopathy, seizures, autonomic neuropathy, optic neuropathy, and peripheral neuropathy. We present the case of a 25-year-old male patient who had a recurrent amoebic liver abscess, received long-term intravenous and oral treatment with metronidazole, and developed cerebellar syndrome and parkinsonism. Electroencephalogram, computed tomography scan, and magnetic resonance imaging of the brain, along with various laboratory tests, revealed no abnormalities. The molecular imaging service performed a dual positron emission tomography imaging with FDG and FDOPA, ruling out neurodegenerative parkinsonism and suggesting a possible pharmacological cause.