Optimal ROI setting on the anatomically normalized I-123 FP-CIT images using high-resolution SPECT

Area of Science:

• Neuroimaging
• Nuclear Medicine
• Dopaminergic System Imaging

Background:

• Accurate quantification of dopamine transporter (DAT) binding is crucial for diagnosing and monitoring neurodegenerative diseases.
• Establishing reliable regions of interest (ROIs) in SPECT imaging is essential for precise DAT binding measurements.
• I-123 FP-CIT SPECT is a key imaging modality for assessing the dopaminergic system.

Purpose of the Study:

• To determine the optimal regions of interest (ROIs) for quantifying dopamine transporter binding in anatomically normalized I-123 FP-CIT SPECT images.
• To compare the suitability of MRI-based versus I-123 FP-CIT SPECT-based ROIs for quantitative analysis.

Main Methods:

• Utilized I-123 FP-CIT SPECT and MRI data from 16 normal controls and 14 Parkinsonian patients.
• Anatomically normalized SPECT images to MNI space using an I-123 FP-CIT template and SPM8.
• Defined ROIs on both MRI and I-123 FP-CIT images for quantitative comparison of specific binding ratios.

Main Results:

• In normal controls, MRI-based ROIs showed lowest binding in the caudate nucleus, while I-123 FP-CIT ROIs showed uniform binding.
• Parkinsonian patients exhibited rostrocaudal decline in binding with I-123 FP-CIT ROIs.
• MRI-based ROIs in patients showed highest binding in the anterior putamen.

Conclusions:

• Developed an ROI template applicable to both MRI and I-123 FP-CIT SPECT images.
• Concluded that I-123 FP-CIT-based ROIs are superior to MRI-based ROIs for quantitative analysis of dopamine transporter binding.
• I-123 FP-CIT SPECT-derived ROIs provide more accurate quantitative values for DAT binding.