Comparison between a dual-head and a brain-dedicated SPECT system in the measurement of the loss of dopamine transporters with [123I]FP-CIT

BACKGROUND: Dual-head SPECT systems are used by many clinical departments for [(123)I]FP-CIT SPECT imaging, while triple-head or brain-dedicated systems with better imaging performance are more commonly used by research institutions. There are limited data comparing the capability of the two types of system to measure dopamine transporter (DAT) loss in vivo. PURPOSE: The aim of this study was to compare the ability of a dual-head and a brain-dedicated SPECT system to estimate the degree of DAT loss in different movement disorders with variable nigrostriatal impairment, with [(123)I]FP-CIT. MATERIALS AND METHODS: Four patients with essential tremor, 24 with Parkinson's disease (PD), six with spinocerebellar ataxia type 2 and six controls were studied with [(123)I]FP-CIT. SPECT scans were performed on a dual-head (E.CAM-Siemens) and subsequently on a brain-dedicated system (Ceraspect-DSI). RESULTS: Striatal DAT outcome measures on the E.CAM and the Ceraspect were strongly correlated and the putamen-to-caudate ratios were almost identical. Although the measured values were lower by 52+/-25% in caudate and by 51+/-31% in putamen on the E.CAM (p