Abstract
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Objectives 123I-β-CIT has an extended phase of uptake suggesting optimal scan time at 18-24 hours PI. We evaluated 4 and 24 hour scans using a regional voxel statistical analysis and compared data to quantitative and qualitative results to decide if same-day imaging is feasible.
Methods A cohort of 23 subjects with suspected, not confirmed Parkinson’s (PS) underwent two 24min acquisitions on a PRISM 3000XP (Philips) at 4 and 24 hrs PI of 5.66mCi (±0.62% SD) 123I-β-CIT. Scans were reconstructed using FBP, Chang0 AC, 3D post-hoc filtering. ROIs were placed on target caudate, putamen and occipital background areas. Striatal binding ratios (V3”) were calculated as the ratio of specific uptake to non-displaceable background for left and right caudate and putamen. Additionally, a voxel-wise method was used to determine areas of regional uptake differences between early and late scans.
Results Qualitative imaging, and clinical diagnosis at 4 h showed concordance in 11/13 (84.6%) clinically positive PS subjects, and 9/10 (90%) non PS subjects. 24 h qualitative imaging was concordant in 12/13 (92.3%) positive PS subjects, and 6/10 (60%) non PS subjects. Quantitative analyses at 4 h notably distinguished PS from non PS, but with less accuracy than 24 h.
Conclusions Presynaptic dopamine transporter imaging with β-CIT is useful in evaluating striatal function; both qualitative and quantitative outcomes were slightly better for the late acquisition than early. Using a regional voxel analysis to determine uptake differences between 4 and 24 hour scans helps to investigate the feasibility of same-day imaging.
- © 2009 by Society of Nuclear Medicine