Head‐to‐head comparison of 18F‐FP‐CIT and 123I‐FP‐CIT for dopamine transporter imaging in patients with Parkinson's disease: A preliminary study

123I‐FP‐CIT and 18F‐FP‐CIT are radiotracers which are widely used to diagnose Parkinson's disease (PD). However, to our knowledge, no studies to date have made head‐to‐head comparisons between 123I‐FP‐CIT and 18F‐FP‐CIT. Therefore, in this study, 123I‐FP‐CIT SPECT/CT was compared with 18F‐FP‐CIT PET/CT in the same cohort of subjects. Patients with PD and essential tremor (ET) underwent 123I‐FP‐CIT SPECT/CT and 18F‐FP‐CIT PET/CT. Visual and semiquantitative analyses were conducted. The specific binding ratio (SBR) and putamen to caudate ratio (PCR) were compared between subjects who underwent 123I‐FP‐CIT SPECT/CT and 18F‐FP‐CIT PET/CT. Visual analysis showed that the striatal uptake of both radiotracers was decreased in the PD group, whereas striatal uptake was intact in the ET group. The SBR between 123I‐FP‐CIT SPECT/CT and 18F‐FP‐CIT PET/CT showed a positive correlation (r = .78, p